diff --git a/src/challenge.ts b/src/challenge.ts
index d697960..ac57497 100644
--- a/src/challenge.ts
+++ b/src/challenge.ts
@@ -33,12 +33,18 @@ interface ReviewedBook extends Book {
  *  //        reviews: [{ reviewer: "Alice", comment: "A thought-provoking novel!" }]
  *  //      }
  */
+
+
 function addReview(
   book: ReviewedBook,
   reviewer: string,
   comment: string
 ): ReviewedBook {
-  // write your code here...
+  // write your code here...  
+  if(book.reviews == undefined) 
+    book.reviews = [{reviewer, comment}]
+  else
+    book.reviews?.push ({reviewer, comment})
 
   return book;
 }
diff --git a/src/objects.ts b/src/objects.ts
index ef6298f..6905b89 100644
--- a/src/objects.ts
+++ b/src/objects.ts
@@ -28,7 +28,12 @@ function createBook(
 ): Book {
   // write your code here...
 
-  return {} as Book; // replace "{} as Book" with what you see is fit
+  return {
+  title: title,
+  author: author,
+  publishedYear: publishedYear,
+  genre: genre
+  } as Book; // replace "{} as Book" with what you see is fit
 }
 
 // DO NOT CHANGE THE LINE OF CODE BELOW (you can use it for testing your code)
@@ -50,8 +55,7 @@ const book = createBook(
  */
 function printBookTitleAndYear(book: Book): string {
   // write your code here...
-
-  return ""; // replace empty string with what you see is fit
+  return `${book.title} ${book["publishedYear"]}` 
 }
 
 /**
@@ -66,7 +70,7 @@ function printBookTitleAndYear(book: Book): string {
  */
 function addPageCount(book: Book, pageCount: number): Book {
   // write your code here...
-
+  book.pageCount = pageCount
   return book;
 }
 
@@ -88,7 +92,7 @@ function addPageCount(book: Book, pageCount: number): Book {
  */
 function addISBN(book: Book, ISBN: string): Book {
   // write your code here...
-
+  book.ISBN = ISBN;
   return book;
 }
 
@@ -110,7 +114,7 @@ function addISBN(book: Book, ISBN: string): Book {
  */
 function updatePublishedYear(book: Book, newYear: number): Book {
   // write your code here...
-
+  book.publishedYear = newYear
   return book;
 }
 
@@ -135,7 +139,9 @@ function updatePublishedYear(book: Book, newYear: number): Book {
  */
 function addSecondAuthor(book: Book, additionalAuthor: string): Book {
   // write your code here...
-
+  let authors = [book.author as string] 
+  authors.push(additionalAuthor)
+  book.author = authors;    
   return book;
 }