001-multiples-of-3-and-5.lhs

#!/usr/bin/env runhaskell

[Multiples of 3 and 5](http://projecteuler.net/problem=1)
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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.


Code
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> main :: IO ()
> main = let result = sum
>                   $ filter (\x -> mod x 5 == 0 || mod x 3 == 0)
>                   $ takeWhile (< 1000) [1 ..]
>                   :: Integer
>        in print result


Answer
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    233168