Quote Originally Posted by Aerith's Knight View Post
Quote Originally Posted by Depression Moon View Post
Question 2
Sum the numbers 10 + 20 + 30 + .... + 500
This is familiar to me and I know there is a simple solution, but I can't remember it.
Sum(10n) with n=1,2,...,50

Or alternatively:

25*[(10+500)/2]

or in n-form:

n/2 * (N+(N-(N-1))/2
Stole the answer out of my liberal arts major ass.