1) Find Greatest Common Divisor (GCD) of 2 numbers using recursion. (25 points)

2) Write a recursive function to reverse a string. Write a recursive function to reverse the words in a string, i.e., boy is walking becomes Walking is boy. (50 points)

3) Write a function for mutliply(a,b), where a and b are both positive integers, but you can only use the + or operators. (25 points)