# Sum Of Multiples

Given a number, find the sum of all the multiples of particular numbers up to
but not including that number.

If we list all the natural numbers up to but not including 20 that are
multiples of either 3 or 5, we get 3, 5, 6 and 9, 10, 12, 15, and 18.

The sum of these multiples is 78.
## Source

A variation on Problem 1 at Project Euler [http://projecteuler.net/problem=1](http://projecteuler.net/problem=1)

## Submitting Incomplete Solutions
It's possible to submit an incomplete solution so you can see how others have completed the exercise.