bugfixed_Evaluation_final

[saketsagar54321]

what kind of pr is this?
-\ kind bug fix.

why this pr is needed?

• this pull request is needed because the file name add.c in evaluation_final repository code was wrong in which num3 is not declared in the code even though num3 is there in the code instead of num2 so through remote repository i have changed or modify the code and no any is there program is running smoothly without any error.

what is the issue number?

• issue- fixes bugfix_evaluationfinal #541

test approach
-\kind not tested