Problem 43. The difference of the two sums

The sum of the first 100 multiples of 4 is: 4+8+12+...+400. The sum of the first 100 multiples of 3 is: 3+6+9+...+300. What number is equal to the difference of the two sums?

Posted by Sergey Sobolev at 3/24/2008 10:32:00 PM