GMAT Problem Solving Question 52: Prime factors

 
Try the following GMAT Problem Solving question on finding prime factors of a summation.

Question 52:

If $S$ is the sum of the first fifty positive integers, then what is the sum of all the distinct prime factors of $S$ ?

1. $\quad 20$

2. $\quad 25$

3. $\quad 32$

4. $\quad 41$

5. $\quad 56$