must be done in c programming

4. (25 points) Answer the following questions. a. (15 pts) The program given below uses a switch-case statement. Re-write the program converting the switch-case statement into an if-else statement. #include void main() { int num scanf("%d".&num): switch(num, case 1: num= num+ break; case 2: case 4: num = num * 2: break; case-1: num = 0; break; default: num=-1 } printf("The result is %d n num): } b. (10 points) (WHO) The age health scale of the world health organization is given below. 0 - 17 adolescents (ergen) 18 - 65 teen (genc) 66 - 79 middle aged (ortayasl) 80 - 99 old. (yasli) The age of a person is entered on the keyboard. Write main routine which does given procedure