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.
In [12]:
let isMultipleThree x = (x % 3) = 0
let isMultipleFive x = (x % 5) = 0
let isMultipleThreeOrFive x = isMultipleThree x || isMultipleFive x
[ 1 .. 999 ]
|> List.filter isMultipleThreeOrFive
|> List.sum
Out[12]: