diff --git a/Gemfile b/Gemfile
new file mode 100644
index 0000000..2133eb0
--- /dev/null
+++ b/Gemfile
@@ -0,0 +1,5 @@
+source "https://rubygems.org"
+
+gem "standard"
+gem "tty-markdown"
+gem "timeout"
diff --git a/Gemfile.lock b/Gemfile.lock
new file mode 100644
index 0000000..cc42973
--- /dev/null
+++ b/Gemfile.lock
@@ -0,0 +1,65 @@
+GEM
+  remote: https://rubygems.org/
+  specs:
+    ast (2.4.2)
+    json (2.6.3)
+    kramdown (2.4.0)
+      rexml
+    language_server-protocol (3.17.0.3)
+    parallel (1.22.1)
+    parser (3.2.1.0)
+      ast (~> 2.4.1)
+    pastel (0.8.0)
+      tty-color (~> 0.5)
+    rainbow (3.1.1)
+    regexp_parser (2.7.0)
+    rexml (3.2.5)
+    rouge (3.30.0)
+    rubocop (1.44.1)
+      json (~> 2.3)
+      parallel (~> 1.10)
+      parser (>= 3.2.0.0)
+      rainbow (>= 2.2.2, < 4.0)
+      regexp_parser (>= 1.8, < 3.0)
+      rexml (>= 3.2.5, < 4.0)
+      rubocop-ast (>= 1.24.1, < 2.0)
+      ruby-progressbar (~> 1.7)
+      unicode-display_width (>= 2.4.0, < 3.0)
+    rubocop-ast (1.26.0)
+      parser (>= 3.2.1.0)
+    rubocop-performance (1.15.2)
+      rubocop (>= 1.7.0, < 2.0)
+      rubocop-ast (>= 0.4.0)
+    ruby-progressbar (1.11.0)
+    standard (1.24.3)
+      language_server-protocol (~> 3.17.0.2)
+      rubocop (= 1.44.1)
+      rubocop-performance (= 1.15.2)
+    strings (0.2.1)
+      strings-ansi (~> 0.2)
+      unicode-display_width (>= 1.5, < 3.0)
+      unicode_utils (~> 1.4)
+    strings-ansi (0.2.0)
+    timeout (0.3.2)
+    tty-color (0.6.0)
+    tty-markdown (0.7.1)
+      kramdown (>= 1.16.2, < 3.0)
+      pastel (~> 0.8)
+      rouge (~> 3.14)
+      strings (~> 0.2.0)
+      tty-color (~> 0.5)
+      tty-screen (~> 0.8)
+    tty-screen (0.8.1)
+    unicode-display_width (2.4.2)
+    unicode_utils (1.4.0)
+
+PLATFORMS
+  x86_64-linux
+
+DEPENDENCIES
+  standard
+  timeout
+  tty-markdown
+
+BUNDLED WITH
+   2.3.26
diff --git a/README.md b/README.md
index 1bcab05..ecb6c38 100644
--- a/README.md
+++ b/README.md
@@ -4,3 +4,14 @@ Sample questions for [Ruby Association Certified Ruby Programmer Examination ver
 
 * [Sample Questions for Silver](silver.md) ([Japanese](silver_ja.md))
 * [Sample Questions for Gold](gold.md) ([Japanese](gold_ja.md))
+
+# Run sample exam
+
+* Silver `ruby test.rb` or `ruby test.rb silver en`
+* Gold `ruby test.rb gold en`
+
+Japanese
+
+* Silver `ruby test.rb silver ja`
+* Gold `ruby test.rb gold ja`
+
diff --git a/gold.md b/gold.md
index cb45dff..8cb837d 100644
--- a/gold.md
+++ b/gold.md
@@ -4,7 +4,7 @@
 
 **Q1. Assume that the following code must have the stated execution result:** 
 
-```
+```ruby
 class Stack
   def initialize
     @contents = []
@@ -25,7 +25,8 @@ p stack.pop
 **Which option can be inserted into `__(1)__`? (Choose two.)**
 
 *A:*
-```
+
+```ruby
 [:push, :pop].each do |name|
   define_method(name) do |*args|
     @contents.send(name, *args)
@@ -34,7 +35,8 @@ end
 ```
 
 *B:*
-```
+
+```ruby
 for name in [:push, :pop]
   define_method(name) do |*args|
     @contents.send(name, *args)
@@ -43,7 +45,8 @@ end
 ```
 
 *C:*
-```
+
+```ruby
 [:push, :pop].each do |name|
   instance_eval(<<-EOF)
     def #{name}(*args)
@@ -54,7 +57,8 @@ end
 ```
 
 *D:*
-```
+
+```ruby
 [:push, :pop].each do |name|
   class_eval(<<-EOF)
     def #{name}(*args)
@@ -68,7 +72,7 @@ end
 
 **Q2. Given the following code:**
 
-```
+```ruby
 module I
 end
 
@@ -97,7 +101,7 @@ p C.ancestors
 
 **Q3. Assume that the following code must have the stated execution result:** 
 
-```
+```ruby
 x = __(1)__
 p x + 1
 
@@ -119,7 +123,7 @@ p x + 1
 
 **Q4. Assume that the following code must have the stated execution result:** 
 
-```
+```ruby
 p ("aaaaaa".."zzzzzz").lazy.select { |e| e.end_with?("f") }.__(1)__
 
 [Execution Result]
@@ -140,7 +144,7 @@ p ("aaaaaa".."zzzzzz").lazy.select { |e| e.end_with?("f") }.__(1)__
 
 **Q5. Assume that the following code must have the stated execution result:** 
 
-```
+```ruby
 def round(n, __(1)__)
   n.round(__(1)__)
 end
@@ -165,7 +169,7 @@ p round(2.5, half: :even)
 
 **Q6. Given the following code:**
 
-```
+```ruby
 class A
   def foo
     self.bar
@@ -207,7 +211,7 @@ An exception is raised
 
 **Q7. Assume that the following code must have the stated execution result.** 
 
-```
+```ruby
 class Greeter
   class << self
     def hello
@@ -236,7 +240,7 @@ Hello there!
 
 **Q8: Assume that the following code must have the stated execution result.**
 
-```
+```ruby
 __(1)__
 
 p multiply_by(4) { 2 + 3 }
@@ -249,7 +253,7 @@ p multiply_by(4) { 2 + 3 }
 
 *A:*
 
-```
+```ruby
 def multiply_by(n, &block)
   n * block.call
 end
@@ -257,7 +261,7 @@ end
 
 *B:*
 
-```
+```ruby
 def multiply_by(n, &block)
   n * block
 end
@@ -265,7 +269,7 @@ end
 
 *C:*
 
-```
+```ruby
 def multiply_by(n)
   n * yield
 end
@@ -273,7 +277,7 @@ end
 
 *D:*
 
-```
+```ruby
 def multiply_by(n)
   n * yield.call
 end
@@ -283,7 +287,7 @@ end
 
 **Q9: Assume that the following code must have the stated execution result.** 
 
-```
+```ruby
 __(1)__
 
 p sum { |e| e << 1 << 5 << 7 }
@@ -296,7 +300,7 @@ p sum { |e| e << 1 << 5 << 7 }
 
 *A:*
 
-```
+```ruby
 def sum(&block)
   array = []
   
@@ -307,7 +311,8 @@ end
 ```
 
 *B:*
-```
+
+```ruby
 def sum(&block)
   array = []
   
@@ -318,7 +323,8 @@ end
 ```
 
 *C:*
-```
+
+```ruby
 def sum
   array = []
   
@@ -329,7 +335,8 @@ end
 ```
 
 *D:*
-```
+
+```ruby
 def sum
   array = []
   
@@ -343,7 +350,7 @@ end
 
 **Q10. Given the following code:** 
 
-```
+```ruby
 class A
   @@x = 1
 end
@@ -378,7 +385,7 @@ p B.x
 
 **Q11. Assume that the following code must have the stated execution result:**
 
-```
+```ruby
 words = ["apple", "banana", "cabbage"]
 pop = Proc.new { words.pop }
 3.times{ puts __(1)__ }
@@ -405,7 +412,7 @@ apple
 
 **Q12. Assume that the following code must have the stated execution result:**
 
-```
+```ruby
 words = ["apple", "banana", "cabbage"]
 pop = __(1)__{ words.pop }
 3.times{ puts pop.call }
@@ -430,7 +437,7 @@ apple
 
 **Q13. Assume that the following code must have the stated execution result.**
 
-```
+```ruby
 add = __(1)__
 puts add.call("hello")
 
@@ -452,7 +459,7 @@ HELLO
 
 **Q14. Assume that the following code must have the stated execution result:**
 
-```
+```ruby
 __(1)__
   x + y
 end
@@ -477,7 +484,7 @@ p add(1, 2)
 
 **Q15. Given the following code:**
 
-```
+```ruby
 def reader_method(s)
   <<~EOF
     def #{s}
@@ -492,21 +499,24 @@ print reader_method("foo")
 **Which option corresponds to the execution result? (Choose one.)**
 
 *A:*
-```
+
+```ruby
     def foo
       @foo
     end
 ```
 
 *B:*
-```
+
+```ruby
   def foo
     @foo
   end
 ```
 
 *C:*
-```
+
+```ruby
 def foo
   @foo
 end
@@ -519,7 +529,7 @@ A syntax error occurs.
 
 **Q16. Assume that the following code must have the stated execution result:**
 
-```
+```ruby
 obj = Object.new
 
 def obj.hello
@@ -548,7 +558,7 @@ Hi!
 
 **Q17. Assume that the following code must have the stated execution result.**
 
-```
+```ruby
 class ShoppingList
   def initialize
     @items = []
@@ -591,7 +601,7 @@ puts list
 
 **Q18. Assume that the following code must have the stated execution result.**
 
-```
+```ruby
 class ShoppingList
   def initialize
     @items = []
@@ -633,7 +643,7 @@ ShoppingList:
 
 **Q19. Assume that the following code must have the stated execution result.**
 
-```
+```ruby
 p __(1)__.flat_map {|z|
   (1..z).flat_map {|x|
     (x..z).select {|y|
@@ -662,7 +672,7 @@ p __(1)__.flat_map {|z|
 
 **Q20. Assume that the following code must have the stated execution result.**
 
-```
+```ruby
 ary = ["foo", "bar", nil, "baz"]
 
 p ary.__(1)__ { |i|
@@ -687,7 +697,7 @@ p ary.__(1)__ { |i|
 
 **Q21. Given the following code:**
 
-```
+```ruby
 a, b, *c = ["apple", "banana", "carrot", "daikon"]
 
 p c
@@ -707,13 +717,14 @@ p c
 
 **Q22: Which code produces the following execution result? (Choose one.)**
 
-```
+```ruby
 [Execution Result]
 [["apple", "banana", "carrot"]]
 ```
 
 *A:*
-```
+
+```ruby
 def fx(*args)
   p(args)
 end
@@ -721,7 +732,8 @@ fx(*["apple", "banana", "carrot"])
 ```
 
 *B:*
-```
+
+```ruby
 def fx(*args)
   p(args)
 end
@@ -729,7 +741,8 @@ fx(["apple", "banana", "carrot"])
 ```
 
 *C:*
-```
+
+```ruby
 def fx(*args)
   p(args)
 end
@@ -737,7 +750,8 @@ fx("apple", "banana", "carrot")
 ```
 
 *D:*
-```
+
+```ruby
 def fx(*args)
   p(*args)
 end
@@ -748,7 +762,7 @@ fx(["apple", "banana", "carrot"])
 
 **Q23. Assume that the following code must have the stated execution result.**
 
-```
+```ruby
 p ["foo", "bar", "baz"].map { __(1)__.upcase }
 
 [Execution Result]
@@ -769,7 +783,7 @@ p ["foo", "bar", "baz"].map { __(1)__.upcase }
 
 **Q24. Given the following code:**
 
-```
+```ruby
 def fx(a:, b: "apple")
   p a
   p b
@@ -781,13 +795,15 @@ fx(b: "banana")
 **Which option corresponds to the execution result?**
 
 *A:*
-```
+
+```ruby
 nil
 apple
 ```
 
 *B:*
-```
+
+```ruby
 nil
 banana
 ```
@@ -802,7 +818,7 @@ An exception is raised
 
 **Q25. Assume that the following code must have the stated execution result.**
 
-```
+```ruby
 def add(x:, y:, **params)
   z = x + y
 
@@ -831,7 +847,7 @@ __(1)__
 
 **Q26: Assume that the following code must have the stated execution result.**
 
-```
+```ruby
 class Speaker
   @message = "Hello!"
 
@@ -864,7 +880,7 @@ Hello!
 
 **Q27. Given the following code:**
 
-```
+```ruby
 class Speaker
   @message = "Hello!"
 
@@ -892,7 +908,7 @@ end
 
 **Q28. Assume that the following code must have the stated execution result.**
 
-```
+```ruby
 def x
   puts "x"
 end
@@ -935,7 +951,7 @@ done!
 
 **Q29. Assume that the following code must have the stated execution result.**
 
-```
+```ruby
 letters = catch(:done) do
   ("a".."z").each do |a|
     ("a".."z").each do |b|
@@ -967,7 +983,7 @@ abc
 
 **Q30. Assume that the following code must have the stated execution result.**
 
-```
+```ruby
 begin
   __(1)__
 rescue
@@ -992,7 +1008,7 @@ OK
 
 **Q31. Given the following code:**
 
-```
+```ruby
 AnError = Class.new(Exception)
 
 begin
@@ -1011,27 +1027,32 @@ end
 **Which option corresponds to the execution result? (Choose one.)**
 
 *A:*
-```
+
+```ruby
 Bare rescue
 ```
 
 *B:* 
-```
+
+```ruby
 StandardError rescue
 ```
 
 *C:* 
-```
+
+```ruby
 AnError rescue
 ```
 
 *D:* 
-```
+
+```ruby
 Exception rescue
 ```
 
 *E:*
-```
+
+```ruby
 AnError rescue
 Exception rescue
 ```
@@ -1040,7 +1061,7 @@ Exception rescue
 
 **Q32. Given the following code:**
 
-```
+```ruby
 AnError = Class.new(Exception)
 
 begin
@@ -1059,27 +1080,32 @@ end
 **Which option corresponds to the execution result? (Choose one.)**
 
 *A:*
-```
+
+```ruby
 Bare rescue
 ```
 
 *B:* 
-```
+
+```ruby
 StandardError rescue
 ```
 
 *C:* 
-```
+
+```ruby
 AnError rescue
 ```
 
 *D:* 
-```
+
+```ruby
 Exception rescue
 ```
 
 *E:*
-```
+
+```ruby
 Exception rescue
 AnError rescue
 ```
@@ -1088,7 +1114,7 @@ AnError rescue
 
 **Q33. Given the following code:**
 
-```
+```ruby
 begin
   "hello".world
 rescue => ex
@@ -1112,7 +1138,7 @@ end
 
 **Q34. Given the following code:**
 
-```
+```ruby
 CustomError = Class.new(StandardError)
 
 def boom
@@ -1144,7 +1170,7 @@ end
 
 **Q35. Given the following code:**
 
-```
+```ruby
 def greeting
   "hello"
 ensure
@@ -1160,27 +1186,27 @@ puts greeting
 
 *A:*
 
-```
+```ruby
 hello
 ```
 
 *B:*
 
-```
+```ruby
 hi
 ```
 
 
 *C:*
 
-```
+```ruby
 Ensure called!
 hello
 ```
 
 *D:*
 
-```
+```ruby
 Ensure called!
 hi
 ```
@@ -1189,7 +1215,7 @@ hi
 
 **Q36. Given the following code:**
 
-```
+```ruby
 class Identity
   def self.this_object
     self
@@ -1214,25 +1240,28 @@ p c == d
 
 *A:* 
 
-```
+```ruby
 true
 true
 ```
 
 *B:*
-```
+
+```ruby
 true
 false
 ```
 
 *C:*
-```
+
+```ruby
 false
 true
 ```
 
 *D:*
-```
+
+```ruby
 false
 false
 ```
@@ -1241,7 +1270,7 @@ false
 
 **Q37. Given the following code:**
 
-```
+```ruby
 class Identity
   def self.this_object
     self.class
@@ -1259,25 +1288,29 @@ p Identity.new.this_object.class
 **Which option corresponds to the execution result? (Choose one.)**
 
 *A:*
-```
+
+```ruby
 Identity
 Identity
 ```
 
 *B:*
-```
+
+```ruby
 Class
 Identity
 ```
 
 *C:*
-```
+
+```ruby
 Object
 Identity
 ```
 
 *D:*
-```
+
+```ruby
 Class
 Object
 ```
@@ -1286,7 +1319,7 @@ Object
 
 **Q38. Given the following code:**
 
-```
+```ruby
 module Mixin
   def this_object
     self
@@ -1327,7 +1360,7 @@ p Identity.new.this_object.class
 
 **Q40. Given the following code:**
 
-```
+```ruby
 module Mixin
   def self.greet
     puts "Hello World!"
@@ -1353,7 +1386,7 @@ end
 
 **Q41. Assume that the following code must have the stated execution result.**
 
-```
+```ruby
 module Mixin
   def greet
     puts "Hello World!"
@@ -1384,7 +1417,7 @@ Hello World!
 
 **Q42. Assume that the following code must have the stated execution result.**
 
-```
+```ruby
 module Mixin
   def greet
     puts "Hello World!"
@@ -1415,7 +1448,7 @@ Hello World!
 
 **Q43. Assume that the following code must have the stated execution result.**
 
-```
+```ruby
 class BaseClass
   private
 
@@ -1439,19 +1472,19 @@ Hello World!
 
 *A:* 
 
-```
+```ruby
 public :greet
 ```
 
 *B:*
 
-```
+```ruby
 protected :greet
 ```
 
 *C:*
 
-```
+```ruby
 def greet
   super
 end
@@ -1459,7 +1492,7 @@ end
 
 *D:*
 
-```
+```ruby
 alias_method :original_greet, :greet
 
 def greet
@@ -1471,7 +1504,7 @@ end
 
 **Q44. Assume that the following code must have the stated execution result:**
 
-```
+```ruby
 h = [1, 2, 3]
 case h
 __(1)__ [x, y]
@@ -1498,7 +1531,7 @@ end
 
 **Q45. Assume that the following code must have the stated execution result:**
 
-```
+```ruby
 class Alphabet
   include Enumerable
 
@@ -1539,7 +1572,7 @@ p set.select { |e| e > "W" }
 
 **Q46. Given the following code:**
 
-```
+```ruby
 class TShirt
   SIZES = [:xs, :s, :m, :l, :xl, :xxl]
 
@@ -1569,7 +1602,7 @@ p medium >= large
 
 *A:*
 
-```
+```ruby
 true
 false
 true
@@ -1578,7 +1611,7 @@ true
 ```
 
 *B:*
-```
+```ruby
 false
 true
 true
@@ -1587,7 +1620,7 @@ false
 ```
 
 *C:*
-```
+```ruby
 false
 false
 false
@@ -1596,7 +1629,7 @@ true
 ```
 
 *D:*
-```
+```ruby
 false
 false
 false
@@ -1611,7 +1644,7 @@ An exception is raised.
 
 **Q47. Given the following code:**
 
-```
+```ruby
 require "date"
 
 date = Date.new(2000, 2, 24)
@@ -1623,25 +1656,25 @@ puts(date >> 12)
 **Which option corresponds to the execution result? (Choose one.)**
 
 *A:*
-```
+```ruby
 2000-02-12
 2000-03-07
 ```
 
 *B:*
-```
+```ruby
 2000-03-07
 2000-02-12
 ```
 
 *C:*
-```
+```ruby
 1999-02-24
 2001-02-24
 ```
 
 *D:*
-```
+```ruby
 1988-02-24
 2012-02-24
 ```
@@ -1650,7 +1683,7 @@ puts(date >> 12)
 
 **Q48. Assume that the following code must have the stated execution result:**
 
-```
+```ruby
 require "time"
 
 t = Time.__(1)__("00000024021993", "%S%M%H%d%m%Y")
@@ -1674,7 +1707,7 @@ puts t.iso8601
 
 **Q49. Assume that the following code must have the stated execution result:**
 
-```
+```ruby
 require "singleton"
 
 class Foo
@@ -1703,7 +1736,7 @@ true
 
 **Q50. Assume that the following code must have the stated execution result:**
 
-```
+```ruby
 require 'forwardable'
 
 class List
diff --git a/gold_ja.md b/gold_ja.md
index 6364923..9c80e61 100644
--- a/gold_ja.md
+++ b/gold_ja.md
@@ -4,7 +4,7 @@
 
 **Q1. 以下の実行結果を出力するコードがあります。**
 
-```
+```ruby
 class Stack
   def initialize
     @contents = []
@@ -25,7 +25,8 @@ p stack.pop
 **__(1)__に入る適切な記述を選択してください。(2つ選択)**
 
 *A:*
-```
+
+```ruby
 [:push, :pop].each do |name|
   define_method(name) do |*args|
     @contents.send(name, *args)
@@ -34,7 +35,8 @@ end
 ```
 
 *B:*
-```
+
+```ruby
 for name in [:push, :pop]
   define_method(name) do |*args|
     @contents.send(name, *args)
@@ -43,7 +45,8 @@ end
 ```
 
 *C:*
-```
+
+```ruby
 [:push, :pop].each do |name|
   instance_eval(<<-EOF)
     def #{name}(*args)
@@ -54,7 +57,8 @@ end
 ```
 
 *D:*
-```
+
+```ruby
 [:push, :pop].each do |name|
   class_eval(<<-EOF)
     def #{name}(*args)
@@ -68,7 +72,7 @@ end
 
 **Q2. 以下のコードがあります。**
 
-```
+```ruby
 module I
 end
 
@@ -97,7 +101,7 @@ p C.ancestors
 
 **Q3. 以下の実行結果を出力するコードがあります。** 
 
-```
+```ruby
 x = __(1)__
 p x + 1
 
@@ -119,7 +123,7 @@ p x + 1
 
 **Q4. 以下の実行結果を出力するコードがあります。** 
 
-```
+```ruby
 p ("aaaaaa".."zzzzzz").lazy.select { |e| e.end_with?("f") }.__(1)__
 
 [実行結果]
@@ -140,7 +144,7 @@ p ("aaaaaa".."zzzzzz").lazy.select { |e| e.end_with?("f") }.__(1)__
 
 **Q5. 以下の実行結果を出力するコードがあります。**
 
-```
+```ruby
 def round(n, __(1)__)
   n.round(__(1)__)
 end
@@ -165,7 +169,7 @@ p round(2.5, half: :even)
 
 **Q6. 以下のコードがあります。**
 
-```
+```ruby
 class A
   def foo
     self.bar
@@ -188,12 +192,14 @@ puts A.new.foo
 **実行結果として正しいものを選択してください。(1つ選択)**
 
 *A:*
-```
+
+```ruby
 baz
 ```
 
 *B:*
-```
+
+```ruby
 quux
 ```
 
@@ -207,7 +213,7 @@ quux
 
 **Q7. 以下の実行結果を出力するコードがあります。** 
 
-```
+```ruby
 class Greeter
   class << self
     def hello
@@ -236,7 +242,7 @@ Hello there!
 
 **Q8: 以下の実行結果を出力するコードがあります。**
 
-```
+```ruby
 __(1)__
 
 p multiply_by(4) { 2 + 3 }
@@ -249,7 +255,7 @@ p multiply_by(4) { 2 + 3 }
 
 *A:*
 
-```
+```ruby
 def multiply_by(n, &block)
   n * block.call
 end
@@ -257,7 +263,7 @@ end
 
 *B:*
 
-```
+```ruby
 def multiply_by(n, &block)
   n * block
 end
@@ -265,7 +271,7 @@ end
 
 *C:*
 
-```
+```ruby
 def multiply_by(n)
   n * yield
 end
@@ -273,7 +279,7 @@ end
 
 *D:*
 
-```
+```ruby
 def multiply_by(n)
   n * yield.call
 end
@@ -283,7 +289,7 @@ end
 
 **Q9: 以下の実行結果を出力するコードがあります。** 
 
-```
+```ruby
 __(1)__
 
 p sum { |e| e << 1 << 5 << 7 }
@@ -296,7 +302,7 @@ p sum { |e| e << 1 << 5 << 7 }
 
 *A:*
 
-```
+```ruby
 def sum(&block)
   array = []
   
@@ -307,7 +313,8 @@ end
 ```
 
 *B:*
-```
+
+```ruby
 def sum(&block)
   array = []
   
@@ -318,7 +325,8 @@ end
 ```
 
 *C:*
-```
+
+```ruby
 def sum
   array = []
   
@@ -329,7 +337,8 @@ end
 ```
 
 *D:*
-```
+
+```ruby
 def sum
   array = []
   
@@ -343,7 +352,7 @@ end
 
 **Q10. 以下のコードがあります。** 
 
-```
+```ruby
 class A
   @@x = 1
 end
@@ -378,7 +387,7 @@ p B.x
 
 **Q11. 以下の実行結果を出力するコードがあります。**
 
-```
+```ruby
 words = ["apple", "banana", "cabbage"]
 pop = Proc.new { words.pop }
 3.times{ puts __(1)__ }
@@ -405,7 +414,7 @@ apple
 
 **Q12. 以下の実行結果を出力するコードがあります。**
 
-```
+```ruby
 words = ["apple", "banana", "cabbage"]
 pop = __(1)__{ words.pop }
 3.times{ puts pop.call }
@@ -430,7 +439,7 @@ apple
 
 **Q13. 以下の実行結果を出力するコードがあります。**
 
-```
+```ruby
 add = __(1)__
 puts add.call("hello")
 
@@ -452,7 +461,7 @@ HELLO
 
 **Q14. 以下の実行結果を出力するコードがあります。**
 
-```
+```ruby
 __(1)__
   x + y
 end
@@ -477,7 +486,7 @@ p add(1, 2)
 
 **Q15. 以下のコードがあります。**
 
-```
+```ruby
 def reader_method(s)
   <<~EOF
     def #{s}
@@ -492,21 +501,24 @@ print reader_method("foo")
 **実行結果として正しいものを選択してください。(1つ選択)**
 
 *A:*
-```
+
+```ruby
     def foo
       @foo
     end
 ```
 
 *B:*
-```
+
+```ruby
   def foo
     @foo
   end
 ```
 
 *C:*
-```
+
+```ruby
 def foo
   @foo
 end
@@ -519,7 +531,7 @@ end
 
 **Q16. 以下の実行結果を出力するコードがあります。**
 
-```
+```ruby
 obj = Object.new
 
 def obj.hello
@@ -548,7 +560,7 @@ Hi!
 
 **Q17. 以下の実行結果を出力するコードがあります。**
 
-```
+```ruby
 class ShoppingList
   def initialize
     @items = []
@@ -591,7 +603,7 @@ puts list
 
 **Q18. 以下の実行結果を出力するコードがあります。**
 
-```
+```ruby
 class ShoppingList
   def initialize
     @items = []
@@ -633,7 +645,7 @@ ShoppingList:
 
 **Q19. 以下の実行結果を出力するコードがあります。**
 
-```
+```ruby
 p __(1)__.flat_map {|z|
   (1..z).flat_map {|x|
     (x..z).select {|y|
@@ -662,7 +674,7 @@ p __(1)__.flat_map {|z|
 
 **Q20. 以下の実行結果を出力するコードがあります。**
 
-```
+```ruby
 ary = ["foo", "bar", nil, "baz"]
 
 p ary.__(1)__ { |i|
@@ -687,7 +699,7 @@ p ary.__(1)__ { |i|
 
 **Q21. 以下のコードがあります。**
 
-```
+```ruby
 a, b, *c = ["apple", "banana", "carrot", "daikon"]
 
 p c
@@ -707,13 +719,14 @@ p c
 
 **Q22: 以下の実行結果を出力するコードを選択してください。(1つ選択)**
 
-```
+```ruby
 [実行結果]
 [["apple", "banana", "carrot"]]
 ```
 
 *A:*
-```
+
+```ruby
 def fx(*args)
   p(args)
 end
@@ -721,7 +734,8 @@ fx(*["apple", "banana", "carrot"])
 ```
 
 *B:*
-```
+
+```ruby
 def fx(*args)
   p(args)
 end
@@ -729,7 +743,8 @@ fx(["apple", "banana", "carrot"])
 ```
 
 *C:*
-```
+
+```ruby
 def fx(*args)
   p(args)
 end
@@ -737,7 +752,8 @@ fx("apple", "banana", "carrot")
 ```
 
 *D:*
-```
+
+```ruby
 def fx(*args)
   p(*args)
 end
@@ -748,7 +764,7 @@ fx(["apple", "banana", "carrot"])
 
 **Q23. 以下の実行結果を出力するコードがあります。**
 
-```
+```ruby
 p ["foo", "bar", "baz"].map { __(1)__.upcase }
 
 [実行結果]
@@ -769,7 +785,7 @@ p ["foo", "bar", "baz"].map { __(1)__.upcase }
 
 **Q24. 以下のコードがあります。**
 
-```
+```ruby
 def fx(a:, b: "apple")
   p a
   p b
@@ -781,13 +797,15 @@ fx(b: "banana")
 **実行結果として正しいものを選択してください。**
 
 *A:*
-```
+
+```ruby
 nil
 apple
 ```
 
 *B:*
-```
+
+```ruby
 nil
 banana
 ```
@@ -802,7 +820,7 @@ banana
 
 **Q25. 以下の実行結果を出力するコードがあります。**
 
-```
+```ruby
 def add(x:, y:, **params)
   z = x + y
 
@@ -831,7 +849,7 @@ __(1)__
 
 **Q26: 以下の実行結果を出力するコードがあります。**
 
-```
+```ruby
 class Speaker
   @message = "Hello!"
 
@@ -864,7 +882,7 @@ Hello!
 
 **Q27. 以下のコードがあります。**
 
-```
+```ruby
 class Speaker
   @message = "Hello!"
 
@@ -892,7 +910,7 @@ end
 
 **Q28. 以下の実行結果を出力するコードがあります。**
 
-```
+```ruby
 def x
   puts "x"
 end
@@ -935,7 +953,7 @@ done!
 
 **Q29. 以下の実行結果を出力するコードがあります。**
 
-```
+```ruby
 letters = catch(:done) do
   ("a".."z").each do |a|
     ("a".."z").each do |b|
@@ -967,7 +985,7 @@ abc
 
 **Q30. 以下の実行結果を出力するコードがあります。**
 
-```
+```ruby
 begin
   __(1)__
 rescue
@@ -992,7 +1010,7 @@ OK
 
 **Q31. 以下のコードがあります。**
 
-```
+```ruby
 AnError = Class.new(Exception)
 
 begin
@@ -1011,27 +1029,32 @@ end
 **実行結果として正しいものを選択してください。(1つ選択)**
 
 *A:*
-```
+
+```ruby
 Bare rescue
 ```
 
 *B:* 
-```
+
+```ruby
 StandardError rescue
 ```
 
 *C:* 
-```
+
+```ruby
 AnError rescue
 ```
 
 *D:* 
-```
+
+```ruby
 Exception rescue
 ```
 
 *E:*
-```
+
+```ruby
 AnError rescue
 Exception rescue
 ```
@@ -1040,7 +1063,7 @@ Exception rescue
 
 **Q32. 以下のコードがあります。**
 
-```
+```ruby
 AnError = Class.new(Exception)
 
 begin
@@ -1059,27 +1082,32 @@ end
 **実行結果として正しいものを選択してください。(1つ選択)**
 
 *A:*
-```
+
+```ruby
 Bare rescue
 ```
 
 *B:* 
-```
+
+```ruby
 StandardError rescue
 ```
 
 *C:* 
-```
+
+```ruby
 AnError rescue
 ```
 
 *D:* 
-```
+
+```ruby
 Exception rescue
 ```
 
 *E:*
-```
+
+```ruby
 Exception rescue
 AnError rescue
 ```
@@ -1088,7 +1116,7 @@ AnError rescue
 
 **Q33. 以下のコードがあります。**
 
-```
+```ruby
 begin
   "hello".world
 rescue => ex
@@ -1112,7 +1140,7 @@ end
 
 **Q34. 以下のコードがあります。**
 
-```
+```ruby
 CustomError = Class.new(StandardError)
 
 def boom
@@ -1144,7 +1172,7 @@ end
 
 **Q35. 以下のコードがあります。**
 
-```
+```ruby
 def greeting
   "hello"
 ensure
@@ -1160,27 +1188,27 @@ puts greeting
 
 *A:*
 
-```
+```ruby
 hello
 ```
 
 *B:*
 
-```
+```ruby
 hi
 ```
 
 
 *C:*
 
-```
+```ruby
 Ensure called!
 hello
 ```
 
 *D:*
 
-```
+```ruby
 Ensure called!
 hi
 ```
@@ -1189,7 +1217,7 @@ hi
 
 **Q36. 以下のコードがあります。**
 
-```
+```ruby
 class Identity
   def self.this_object
     self
@@ -1214,25 +1242,28 @@ p c == d
 
 *A:* 
 
-```
+```ruby
 true
 true
 ```
 
 *B:*
-```
+
+```ruby
 true
 false
 ```
 
 *C:*
-```
+
+```ruby
 false
 true
 ```
 
 *D:*
-```
+
+```ruby
 false
 false
 ```
@@ -1241,7 +1272,7 @@ false
 
 **Q37. 以下のコードがあります。**
 
-```
+```ruby
 class Identity
   def self.this_object
     self.class
@@ -1259,25 +1290,29 @@ p Identity.new.this_object.class
 **実行結果として正しいものを選択してください。(1つ選択)**
 
 *A:*
-```
+
+```ruby
 Identity
 Identity
 ```
 
 *B:*
-```
+
+```ruby
 Class
 Identity
 ```
 
 *C:*
-```
+
+```ruby
 Object
 Identity
 ```
 
 *D:*
-```
+
+```ruby
 Class
 Object
 ```
@@ -1286,7 +1321,7 @@ Object
 
 **Q38. 以下のコードがあります。**
 
-```
+```ruby
 module Mixin
   def this_object
     self
@@ -1327,7 +1362,7 @@ p Identity.new.this_object.class
 
 **Q40. 以下のコードがあります。**
 
-```
+```ruby
 module Mixin
   def self.greet
     puts "Hello World!"
@@ -1353,7 +1388,7 @@ end
 
 **Q41. 以下の実行結果を出力するコードがあります。**
 
-```
+```ruby
 module Mixin
   def greet
     puts "Hello World!"
@@ -1384,7 +1419,7 @@ Hello World!
 
 **Q42. 以下の実行結果を出力するコードがあります。**
 
-```
+```ruby
 module Mixin
   def greet
     puts "Hello World!"
@@ -1415,7 +1450,7 @@ Hello World!
 
 **Q43. 以下の実行結果を出力するコードがあります。**
 
-```
+```ruby
 class BaseClass
   private
 
@@ -1439,19 +1474,19 @@ Hello World!
 
 *A:* 
 
-```
+```ruby
 public :greet
 ```
 
 *B:*
 
-```
+```ruby
 protected :greet
 ```
 
 *C:*
 
-```
+```ruby
 def greet
   super
 end
@@ -1459,7 +1494,7 @@ end
 
 *D:*
 
-```
+```ruby
 alias_method :original_greet, :greet
 
 def greet
@@ -1471,7 +1506,7 @@ end
 
 **Q44. 以下の実行結果を出力するコードがあります。**
 
-```
+```ruby
 h = [1, 2, 3]
 case h
 __(1)__ [x, y]
@@ -1498,7 +1533,7 @@ end
 
 **Q45. 以下の実行結果を出力するコードがあります。**
 
-```
+```ruby
 class Alphabet
   include Enumerable
 
@@ -1539,7 +1574,7 @@ p set.select { |e| e > "W" }
 
 **Q46. 以下のコードがあります。**
 
-```
+```ruby
 class TShirt
   SIZES = [:xs, :s, :m, :l, :xl, :xxl]
 
@@ -1569,7 +1604,7 @@ p medium >= large
 
 *A:*
 
-```
+```ruby
 true
 false
 true
@@ -1578,7 +1613,8 @@ true
 ```
 
 *B:*
-```
+
+```ruby
 false
 true
 true
@@ -1587,7 +1623,8 @@ false
 ```
 
 *C:*
-```
+
+```ruby
 false
 false
 false
@@ -1596,7 +1633,8 @@ true
 ```
 
 *D:*
-```
+
+```ruby
 false
 false
 false
@@ -1611,7 +1649,7 @@ false
 
 **Q47. 以下のコードがあります。**
 
-```
+```ruby
 require "date"
 
 date = Date.new(2000, 2, 24)
@@ -1623,25 +1661,29 @@ puts(date >> 12)
 **実行結果として正しいものを選択してください。(1つ選択)**
 
 *A:*
-```
+
+```ruby
 2000-02-12
 2000-03-07
 ```
 
 *B:*
-```
+
+```ruby
 2000-03-07
 2000-02-12
 ```
 
 *C:*
-```
+
+```ruby
 1999-02-24
 2001-02-24
 ```
 
 *D:*
-```
+
+```ruby
 1988-02-24
 2012-02-24
 ```
@@ -1650,7 +1692,7 @@ puts(date >> 12)
 
 **Q48. 以下の実行結果を出力するコードがあります。**
 
-```
+```ruby
 require "time"
 
 t = Time.__(1)__("00000024021993", "%S%M%H%d%m%Y")
@@ -1674,7 +1716,7 @@ puts t.iso8601
 
 **Q49. 以下の実行結果を出力するコードがあります。**
 
-```
+```ruby
 require "singleton"
 
 class Foo
@@ -1703,7 +1745,7 @@ true
 
 **Q50. 以下の実行結果を出力するコードがあります。**
 
-```
+```ruby
 require 'forwardable'
 
 class List
diff --git a/silver.md b/silver.md
index 975c407..538f744 100644
--- a/silver.md
+++ b/silver.md
@@ -32,7 +32,7 @@
 
 **Q4. Which of the following can be inserted into `__(1)__`  in order to generate the output below? (Choose two.)** 
 
-```
+```ruby
 $code = "CODE"
 __(1)__
 
@@ -49,7 +49,7 @@ i like writing CODE
 
 **Q5. Given the following:** 
 
-```
+```ruby
 num = 025
 puts num
 ```
@@ -65,7 +65,7 @@ puts num
 
 **Q6. Given the following:**
 
-```
+```ruby
 x = "Hello"
 y = x.empty? ? 1 : 2
 p y
@@ -82,7 +82,7 @@ p y
 
 **Q7. Given the following:**
 
-```
+```ruby
 amount = 120
 
 size = case amount
@@ -106,7 +106,7 @@ p size
 
 **Q8. Given the following:**
 
-```
+```ruby
 item = "apple"
 
 ["banana", "carrot", "daikon"].each do |item|
@@ -125,7 +125,8 @@ A syntax error occurs
 An exception is raised
 
 *(c)*
-```
+
+```ruby
 banana
 carrot
 daikon
@@ -133,7 +134,8 @@ daikon
 ```
 
 *(d)*
-```
+
+```ruby
 banana
 carrot
 daikon
@@ -144,7 +146,7 @@ apple
 
 **Q9. Given the following:**
 
-```
+```ruby
 x = 0
 
 4.times do |i|
@@ -166,7 +168,7 @@ p x
 
 **Q10. Given the following:**
 
-```
+```ruby
 s = "abcde"
 p s.each_char.map { |i|
   i * 2
@@ -185,7 +187,7 @@ p s.each_char.map { |i|
 
 **Q11. Given the following:**
 
-```
+```ruby
 p "cocoa".chars.tally
 ```
 
@@ -200,7 +202,7 @@ p "cocoa".chars.tally
 
 **Q12. Which of the following can be inserted into `__(1)__`  in order to generate the output below? (Choose one.)** 
 
-```
+```ruby
 puts "blah blah blah".__(1)__(/blah/, "yay")
 
 [Output]
@@ -216,7 +218,7 @@ yay yay yay
 
 **Q13. Given the following:**
 
-```
+```ruby
 s = "pear"
 
 if s.empty?
@@ -239,7 +241,7 @@ end
 
 **Q14: Given the following:**
 
-```
+```ruby
 ["foo: abc", "bar: 100"].each do |i|
   p i.slice(/[0-9]+/)&.to_i
 end
@@ -248,19 +250,22 @@ end
 **Which is the correct result? (Choose one.)**
 
 *(a)*
-```
+
+```ruby
 0
 100
 ```
 
 *(b)*
-```
+
+```ruby
 nil
 100
 ```
 
 *(c)*
-```
+
+```ruby
 false
 100
 ```
@@ -275,7 +280,7 @@ An error occurs at run-time.
 
 **Q15: Given the following:**
 
-```
+```ruby
 def foo(x: 1, y: 2, z: 3)
   p [x, y, z]
 end
@@ -294,7 +299,7 @@ foo(y: 4, z: 5)
 
 **Q16: Which of the following can be inserted into `__(1)__`  in order for the given code to generate the output below? (Choose one.)** 
 
-```
+```ruby
 def foo(x:, y:, z:)
   p [x, y, z]
 end
@@ -323,7 +328,7 @@ __(1)__
 
 **Q18.Given the following:**
 
-```
+```ruby
 MSG = 42
 MSG += 5
 p MSG
@@ -340,7 +345,7 @@ p MSG
 
 **Q19. Given the following:**
 
-```
+```ruby
 MSG = "hello"
 MSG.upcase!
 p MSG
@@ -367,7 +372,7 @@ p MSG
 
 **Q21. Given the following:**
 
-```
+```ruby
 x = [1,2,3,4,5,6,7,8]
 y = x
 x.reject! { |e| e.even? }
@@ -379,25 +384,29 @@ p y
 
 
 *(a)*
-```
+
+```ruby
 [1, 3, 5, 7]
 [1, 2, 3, 4, 5, 6, 7, 8]
 ```
 
 *(b)*
-```
+
+```ruby
 [1, 2, 3, 4, 5, 6, 7, 8]
 [1, 2, 3, 4, 5, 6, 7, 8]
 ```
 
 *(c)*
-```
+
+```ruby
 [1, 3, 5, 7]
 [1, 3, 5, 7]
 ```
 
 *(d)*
-```
+
+```ruby
 [1, 3, 5, 7]
 [2, 4, 6, 8]
 ```
@@ -406,7 +415,7 @@ p y
 
 **Q22. Given the following:**
 
-```
+```ruby
 a = [ 2, 4, 6, 8, 10 ]
 a.shift
 a.pop
@@ -425,7 +434,7 @@ p a
 
 **Q23. Which of the following can be inserted into `__(1)__`  in order for the given code to generate the output below? (Choose one.)** 
 
-```
+```ruby
 x = true
 x __(1)__ exit(1)
 puts("succeeded!")
@@ -444,7 +453,7 @@ succeeded!
 
 **Q24. Given the following:**
 
-```
+```ruby
 m = true
 m or n = true
 p n
@@ -462,7 +471,7 @@ p n
 
 **Q25. Which of the following can be inserted into __(1)__  in order for the given code to generate the output below? (Choose two.)** 
 
-```
+```ruby
 x = [ 9, 7, 5, 3, 1 ]
 p __(1)__
 
@@ -479,7 +488,7 @@ p __(1)__
 
 **Q26. Which of the following can be inserted into __(1)__  in order for the given code to generate the output below? (Choose two.)** 
 
-```
+```ruby
 ary = [ 1, 2, 3, 4, 5 ]
 p ary.__(1)__ { |i| i.odd? }
 
@@ -497,7 +506,7 @@ p ary.__(1)__ { |i| i.odd? }
 
 **Q27. Given the following:**
 
-```
+```ruby
 puts "42A7".to_i
 ```
 
@@ -512,7 +521,7 @@ puts "42A7".to_i
 
 **Q28. Which of the following methods will NOT show you if the element `:c` exists in the hash key or not? (Choose one.)**
 
-```
+```ruby
 h = {a: 2, b: 4, c: 6, d: 8, e: 10}
 ```
 
@@ -526,7 +535,7 @@ h = {a: 2, b: 4, c: 6, d: 8, e: 10}
 
 **Q29. "Which of the following can be inserted into `__(1)__`  in order for the given code to generate the output below? (Choose two.)** 
 
-```
+```ruby
 a = [120, 40, 20, 80, 160, 60, 180]
 a.__(1)__
 p a
@@ -546,7 +555,7 @@ p a
 
 **Q30. Which of the following can be inserted into `__(1)__`  in order for the given code to generate the output below? (Choose one.)**
 
-```
+```ruby
 p ["apple", "banana"] __(1)__ ["banana", "carrot"]
 
 [Output]
@@ -563,7 +572,7 @@ p ["apple", "banana"] __(1)__ ["banana", "carrot"]
 
 **Q31. Given the following:**
 
-```
+```ruby
 p %i(x1 x2 x3)
 ```
 
@@ -578,7 +587,7 @@ What is the correct result? (Choose one.)
 
 **Q32. Given the following:**
 
-```
+```ruby
 class SomeError < StandardError; end
 class SomeOtherError < SomeError; end
 
@@ -606,7 +615,7 @@ What is the correct result? (Choose one.)
 
 **Q33. Given the following:**
 
-```
+```ruby
 begin
   ans = 100/0
   puts ans
@@ -660,7 +669,7 @@ Error: ZeroDivisionError
 
 **Q35. Given the following:**
 
-```
+```ruby
 class Object
   def moo
     puts "MOO!"
@@ -681,7 +690,7 @@ end
 
 **Q36. Which of the following can be inserted into `__(1)__`  in order for the given code to generate the output below? (Choose one.)** 
 
-```
+```ruby
 class Shouter
   def __(1)__(message)
     @message = message
@@ -708,7 +717,7 @@ HELLO, WORLD!
 
 **Q37. Which of the following can be inserted into `__(1)__`  in order for the given code to generate the output below? (Choose one.)** 
 
-```
+```ruby
 class Shouter
   def initialize(message)
     @message = message
@@ -735,7 +744,7 @@ HELLO, WORLD!
 
 **Q38. Given the following:**
 
-```
+```ruby
 class Foo
   attr_reader :var
   def initialize
@@ -766,7 +775,7 @@ puts bar.var
 
 **Q39. Which of the following can be inserted into `__(1)__`  in order for the given code to generate the output below? (Choose two.)**
 
-```
+```ruby
 puts "$foo$".__(1)__("$")
 
 [Output]
@@ -782,7 +791,7 @@ foo$
 
 **Q40. Which of the following can be inserted into `__(1)__`  in order for the given code to generate the output below? (Choose one.)**
 
-```
+```ruby
 r = "a".."e"
 p r.__(1)__
 
@@ -799,7 +808,7 @@ p r.__(1)__
 
 **Q41. Given the following:**
 
-```
+```ruby
 p [0,1,2,3,4,5].find {|x| x < 3}
 ```
 
@@ -814,7 +823,7 @@ p [0,1,2,3,4,5].find {|x| x < 3}
 
 **Q42. Which of the following can be inserted into `__(1)__`  in order for the given code to generate the output below? (Choose two.)** 
 
-```
+```ruby
 p [1,16,8,4,2].__(1)__
 
 [Output]
@@ -831,7 +840,7 @@ p [1,16,8,4,2].__(1)__
 
 **Q43. Which of the following can be inserted into __(1)__ in order for the given code to sort an array in descending order? (Choose one.)**
 
-```
+```ruby
 ary = [2,4,8,1,16]
 p ary.__(1)__
 
@@ -848,7 +857,7 @@ p ary.__(1)__
 
 **Q44. Given the following:**
 
-```
+```ruby
 File.write("test", "hellorubyworld\n")
 File.open("test") do |file|
   file.seek(5)
@@ -868,7 +877,7 @@ end
 
 **Q45. The code below was used to open a file omitting the second argument of the open method.  In this case, which of the following is implicitly specified? (Choose one.)**
 
-```
+```ruby
 file = open("sample.txt")
 ```
 
@@ -885,7 +894,7 @@ file = open("sample.txt")
 
 **In the case that the “test_two.txt” file already exist, this code should set first the file size to zero and then overwrites its content from the beginning. (Choose two.)**
 
-```
+```ruby
 open("test_one.txt") {|source|
   open("test_two.txt", "__(1)__") {|dest|
     dest.write(source.read)
@@ -913,7 +922,7 @@ open("test_one.txt") {|source|
 
 **Q48. Given the following:**
 
-```
+```ruby
 p "hello ruby world"[6,4]
 ```
 
@@ -930,7 +939,7 @@ p "hello ruby world"[6,4]
 
 Given the following:
 
-```
+```ruby
 str = "bat"
 str[1,1] = "o"
 p str
@@ -947,7 +956,7 @@ Which is the correct output? (Choose one.)
 
 **Q50. Given the following:**
 
-```
+```ruby
 puts 5 * "hi"
 ```
 
diff --git a/silver_answers_ja.md b/silver_answers_ja.md
index 500378e..06cd549 100644
--- a/silver_answers_ja.md
+++ b/silver_answers_ja.md
@@ -247,7 +247,7 @@ Another approach is to use a range, which generates a subarray based the index v
 
 ---------------------------------------------------------------------------
 
-**A28. (b)**
+**A28: (b)**
 
 `has_key?`、`include?`、`key?`、`member?`はすべて同じメソッドの別名で、与えられたキーがハッシュに存在する場合`true`を、存在しない場合`false`を返します。
 
diff --git a/silver_ja.md b/silver_ja.md
index 69c4ad7..be8fce1 100644
--- a/silver_ja.md
+++ b/silver_ja.md
@@ -66,7 +66,7 @@ puts num
 
 **Q6. 以下のコードがあります。**
 
-```
+```ruby
 x = "Hello"
 y = x.empty? ? 1 : 2
 p y
@@ -83,7 +83,7 @@ p y
 
 **Q7. 以下のコードがあります。**
 
-```
+```ruby
 amount = 120
 
 size = case amount
@@ -107,7 +107,7 @@ p size
 
 **Q8. 以下のコードがあります。**
 
-```
+```ruby
 item = "apple"
 
 ["banana", "carrot", "daikon"].each do |item|
@@ -126,7 +126,8 @@ puts item
 例外が発生する
 
 *(c)*
-```
+
+```ruby
 banana
 carrot
 daikon
@@ -134,7 +135,8 @@ daikon
 ```
 
 *(d)*
-```
+
+```ruby
 banana
 carrot
 daikon
@@ -145,7 +147,7 @@ apple
 
 **Q9. 以下のコードがあります。**
 
-```
+```ruby
 x = 0
 
 4.times do |i|
@@ -167,7 +169,7 @@ p x
 
 **Q10. 以下のコードがあります。**
 
-```
+```ruby
 s = "abcde"
 p s.each_char.map { |i|
   i * 2
@@ -186,7 +188,7 @@ p s.each_char.map { |i|
 
 **Q11. 以下のコードがあります。**
 
-```
+```ruby
 p "cocoa".chars.tally
 ```
 
@@ -218,7 +220,7 @@ yay yay yay
 
 **Q13. 以下のコードがあります。**
 
-```
+```ruby
 s = "pear"
 
 if s.empty?
@@ -241,7 +243,7 @@ end
 
 **Q14: 以下のコードがあります。**
 
-```
+```ruby
 ["foo: abc", "bar: 100"].each do |i|
   p i.slice(/[0-9]+/)&.to_i
 end
@@ -250,19 +252,22 @@ end
 **実行結果として正しいものを選択してください。(1つ選択)**
 
 *(a)*
-```
+
+```ruby
 0
 100
 ```
 
 *(b)*
-```
+
+```ruby
 nil
 100
 ```
 
 *(c)*
-```
+
+```ruby
 false
 100
 ```
@@ -277,7 +282,7 @@ false
 
 **Q15: 以下のコードがあります。**
 
-```
+```ruby
 def foo(x: 1, y: 2, z: 3)
   p [x, y, z]
 end
@@ -326,7 +331,7 @@ __(1)__
 
 **Q18.以下のコードがあります。**
 
-```
+```ruby
 MSG = 42
 MSG += 5
 p MSG
@@ -343,7 +348,7 @@ p MSG
 
 **Q19. 以下のコードがあります。**
 
-```
+```ruby
 MSG = "hello"
 MSG.upcase!
 p MSG
@@ -370,7 +375,7 @@ p MSG
 
 **Q21. 以下のコードがあります。**
 
-```
+```ruby
 x = [1,2,3,4,5,6,7,8]
 y = x
 x.reject! { |e| e.even? }
@@ -382,25 +387,29 @@ p y
 
 
 *(a)*
-```
+
+```ruby
 [1, 3, 5, 7]
 [1, 2, 3, 4, 5, 6, 7, 8]
 ```
 
 *(b)*
-```
+
+```ruby
 [1, 2, 3, 4, 5, 6, 7, 8]
 [1, 2, 3, 4, 5, 6, 7, 8]
 ```
 
 *(c)*
-```
+
+```ruby
 [1, 3, 5, 7]
 [1, 3, 5, 7]
 ```
 
 *(d)*
-```
+
+```ruby
 [1, 3, 5, 7]
 [2, 4, 6, 8]
 ```
@@ -409,7 +418,7 @@ p y
 
 **Q22. 以下のコードがあります。**
 
-```
+```ruby
 a = [ 2, 4, 6, 8, 10 ]
 a.shift
 a.pop
@@ -448,7 +457,7 @@ succeeded!
 
 **Q24. 以下のコードがあります。**
 
-```
+```ruby
 m = true
 m or n = true
 p n
@@ -503,7 +512,7 @@ p ary.__(1)__ { |i| i.odd? }
 
 **Q27. 以下のコードがあります。**
 
-```
+```ruby
 puts "42A7".to_i
 ```
 
@@ -518,7 +527,7 @@ puts "42A7".to_i
 
 **Q28. 次のメソッドのうち`:c`がハッシュのキーとして存在するかどうかを「返さない」ものを選択してください。(1つ選択)**
 
-```
+```ruby
 h = {a: 2, b: 4, c: 6, d: 8, e: 10}
 ```
 
@@ -571,7 +580,7 @@ p ["apple", "banana"] __(1)__ ["banana", "carrot"]
 
 **Q31. 以下のコードがあります。**
 
-```
+```ruby
 p %i(x1 x2 x3)
 ```
 
@@ -586,7 +595,7 @@ p %i(x1 x2 x3)
 
 **Q32. 以下のコードがあります。**
 
-```
+```ruby
 class SomeError < StandardError; end
 class SomeOtherError < SomeError; end
 
@@ -614,7 +623,7 @@ end
 
 **Q33. 以下のコードがあります。**
 
-```
+```ruby
 begin
   ans = 100/0
   puts ans
@@ -629,7 +638,8 @@ end
 **実行結果として正しいものを選択してください。(1つ選択)**
 
 *(a)*
-```
+
+```ruby
 0
 DONE!
 ```
@@ -641,13 +651,15 @@ Error: ZeroDivisionError
 ```
 
 *(c)*
-```
+
+```ruby
 Error: ZeroDivisionError
 DONE!
 ```
 
 *(d)*
-```
+
+```ruby
 Error: ZeroDivisionError
 0
 ```
@@ -668,7 +680,7 @@ Error: ZeroDivisionError
 
 **Q35. 以下のコードがあります。**
 
-```
+```ruby
 class Object
   def moo
     puts "MOO!"
@@ -745,7 +757,7 @@ HELLO, WORLD!
 
 **Q38. 以下のコードがあります。**
 
-```
+```ruby
 class Foo
   attr_reader :var
   def initialize
@@ -811,7 +823,7 @@ p r.__(1)__
 
 **Q41. 以下のコードがあります。**
 
-```
+```ruby
 p [0,1,2,3,4,5].find {|x| x < 3}
 ```
 
@@ -862,7 +874,7 @@ p ary.__(1)__
 
 **Q44. 以下のコードがあります。**
 
-```
+```ruby
 File.write("test", "hellorubyworld\n")
 File.open("test") do |file|
   file.seek(5)
@@ -882,7 +894,7 @@ end
 
 **Q45. 以下のコードではopenメソッドの第2引数を省略してファイルを開いています。このケースで暗黙的に第2引数として指定されるものを選択してください。**
 
-```
+```ruby
 file = open("sample.txt")
 ```
 
@@ -928,7 +940,7 @@ open("test_one.txt") {|source|
 
 **Q48. 以下のコードがあります。**
 
-```
+```ruby
 p "hello ruby world"[6,4]
 ```
 
@@ -962,7 +974,7 @@ p str
 
 **Q50. 以下のコードがあります。**
 
-```
+```ruby
 puts 5 * "hi"
 ```
 
diff --git a/test.rb b/test.rb
new file mode 100644
index 0000000..65a7658
--- /dev/null
+++ b/test.rb
@@ -0,0 +1,188 @@
+require "tty-markdown"
+require "timeout"
+
+class Test
+  attr_reader :questions, :answers, :howto
+
+  DURATION = 60 * 90
+
+  class Exit < StandardError; end
+
+  class EndOfTime < StandardError; end
+
+  def initialize(type: :silver, language: :en)
+    case type
+    when :silver
+      @questions = File.read("silver#{(language == :en) ? "" : "_ja"}.md").split(/^-------------.*\n/)[0..49]
+      @answers = File.read("silver_answers#{(language == :en) ? "" : "_ja"}.md").split(/^-------------.*\n/)[0..49]
+      @answers.map! do |ans|
+        ans.slice(/^\*\*A\d+:.*/).scan(/\(([a-z])\)/).flatten(1).map { |i|
+          i.ord - "a".ord
+        }
+      end
+      @test_symbol = "a"
+    when :gold
+      @questions = File.read("gold#{(language == :en) ? "" : "_ja"}.md").split(/^-------------.*\n/)[0..49]
+      @answers = File.read("gold_answers#{(language == :en) ? "" : "_ja"}.md").split(/^-------------.*\n/)[0..49]
+      @answers.map! do |ans|
+        ans.slice(/^\*\*A\d+:.*/).scan(/\(([A-Z])\)/).flatten(1).map { |i|
+          i.ord - "A".ord
+        }
+      end
+      @test_symbol = "A"
+    else
+      raise StandardError, "test not found"
+    end
+    @howto = File.read("test_readme.md")
+    @last_printed_lines_count = 0
+  end
+
+  def start
+    clean_the_screen
+    print_howto
+    clean_the_screen
+    Timeout.timeout(DURATION, EndOfTime) do
+      @exam_started = true
+      exam
+    end
+  rescue Exit
+    clean_the_screen
+    calc_and_print_result(@result)
+  rescue EndOfTime
+    clean_the_screen
+    puts "# Time for exam has runned out"
+    calc_and_print_result(@result)
+  end
+
+  private
+
+  def exam
+    @curr_inx = -1
+    @result = Array.new(50)
+    @user_answers = Array.new(50)
+    loop do
+      next_question
+      user_input = get_user_input
+      case user_input
+      when :repeat
+        @curr_inx -= 1
+        next
+      when :next
+        next
+      when :prev
+        @curr_inx -= 2
+        next
+      when :howto
+        @curr_inx -= 1
+        clean_the_screen
+        print_howto
+        clean_the_screen
+      else
+        @user_answers[@curr_inx] = user_input
+        @result[@curr_inx] = validate_answer(user_input)
+      end
+    end
+  end
+
+  def next_question
+    @curr_inx += 1 if @curr_inx < 49
+    clean_the_screen
+    question = questions[@curr_inx]
+    puts question
+    if @user_answers[@curr_inx]
+      prev_answ = @user_answers[@curr_inx].map { |i| (@test_symbol.ord + i).chr }.join(",")
+      puts "## Your previously entered answer is **(#{prev_answ})**"
+    end
+  end
+
+  def validate_answer(user_answers)
+    user_answers.sort == answers[@curr_inx].sort
+  end
+
+  def get_user_input
+    puts "**Write you answers separated by commas:**"
+    user_answer = gets.chomp
+    case user_answer
+    in /exit/i
+      puts "**Are you sure want finish exam? (Enter `yes` to exit)**"
+      raise Exit if gets.match?(/yes/i)
+
+      :repeat
+    in /\A(n|next|continue)\z/i
+      :next
+    in /\A(p|previous|prev\z)/i
+      :prev
+    in /\Agoto (\d+)\z/
+      return :repeat unless $1.to_i.between?(1, 50)
+
+      @curr_inx = $1.to_i - 1
+      :repeat
+    in /\A(stop|finish|end\z)/i
+      puts "**Are you sure want finish exam? (Enter `yes` to exit)**"
+      raise Exit if gets.match?(/yes/i)
+
+      :repeat
+    in /\A(help|h)\z/i
+      puts <<~MD
+        # Available commands
+        - `howto` - print the text that was printend at start (don't restart the exam)
+        - `n` or `next` or `continue` - to go to the next question in order
+        - `p` or `prev` or `previous` - to go to the previous question in order
+        - `stop` or `finish` or `end` - to finish the exam and print your results
+        - `h` or `help` - to print this text
+
+        **Press enter to continue**
+      MD
+      gets
+
+      :repeat
+    in /\Ahowto\z/i
+      :howto
+    else
+      user_answer.strip.split(",").map { |e| e.ord - @test_symbol.ord }
+    end
+  end
+
+  def calc_and_print_result(result)
+    correct_answers_count = result.count { |e| 1 if e }
+    correct_answers_percecnt = correct_answers_count.to_f / questions.length * 100
+    puts "Your result is **#{correct_answers_count} out of #{questions.length}**"
+    puts "Percent of **correct answers is #{correct_answers_percecnt.round(2)}%**"
+    if correct_answers_count >= 75.0
+      puts "## You've passed the test exam"
+    else
+      puts "## You've failed the test exam."
+      puts "### Don't give up! You can do it! (="
+    end
+  end
+
+  def print_howto
+    puts howto.to_s
+    if @exam_started
+      puts "**Press enter to continue**"
+      gets
+    else
+      puts "## To start the test enter `y`"
+      raise Exit unless gets.chomp.match?(/\Ay\z/)
+    end
+  end
+
+  def clean_the_screen
+    print "\033[2J\033[3J\033[1;1H"
+  end
+
+  def puts(string)
+    Kernel.puts TTY::Markdown.parse(string).to_s
+  end
+end
+
+test_type = ARGV[0]&.to_sym || :silver
+test_language = ARGV[1]&.to_sym || :en
+
+ARGV.clear
+if test_type.match?("help")
+  puts TTY::Markdown.parse(File.read("test_help.md")).to_s
+else
+  test = Test.new(type: test_type, language: test_language)
+  test.start
+end
diff --git a/test_help.md b/test_help.md
new file mode 100644
index 0000000..e5a05c3
--- /dev/null
+++ b/test_help.md
@@ -0,0 +1,15 @@
+Usage: `ruby test.rb [testname] [locale]`
+
+**testname**: 
+  pass the name of the test that you want to run
+  could be a `gold` or `silver` or `help`
+  the default value is `silver`
+  `help` would print this message
+  Example: 
+    `ruby test.rb gold`
+**locale**:
+  can be `en` or `ja` or `jp`
+  default is `en`. 
+  [secret information]
+  if you pass any word that isn't `en` 
+    it would accepted as `jp` =)
diff --git a/test_readme.md b/test_readme.md
new file mode 100644
index 0000000..d8064cb
--- /dev/null
+++ b/test_readme.md
@@ -0,0 +1,37 @@
+# Welcome to ruby exam preparation
+
+## ATTENTION
+If you keep the test it would flush your terminal buffer.
+Enter `y` in case you agree with that.
+
+### Notice
+Recomend **open this test in new terminal** 
+for simply navigation over printed questions
+
+### Duration 
+The test duration is **90 minutes**. 
+If you exceed the time, test would be interrupted 
+and you will get the result
+
+### How to answer
+When you'll answer on questions please 
+  use the same register of bullet points as used in questions.
+
+#### Example:
+
+**Q1 Some text of question**
+
+- (A) 
+```ruby
+  puts "answer"
+  # here might be the code or smth
+```
+- (B) answer
+- (C) answer
+- (D) answer
+
+Write you answers separated by commas:
+
+A,B,C
+
+----------------------------------------