Hi everyone ! this is the problem that I tried to solve using python :
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.

So I will send you my work on python to make sure to Its correctness .
have you another solution that you find 'more efficient ' ? thank you !