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.
Click “More” for my solution.
I decided on a quick and simple brute force approach. There are clearly many more efficient ways of doing this, however the code below solves the problem in reasonable time.
The timings were taken on a Genuine Intel(R) CPU U1400 @ 1.20GHz with 1GB RAM.