Multiples of 3 and 5

Problem 1

Published on Friday, 5th October 2001, 06:00 pm; Solved by 382178

If we list all the natural numbers below 10 that are multiples of 3 or 5, we get 3, 5, 6 and 9. The sum of these multiples is 23.

Find the sum of all the multiples of 3 or 5 below 1000.