Project Euler #1: Multiples of 3 or 5

This article is part of a series where I'll be diving head first into the Project Euler puzzles. I want to document the challenge of solving such a puzzle and how I got to the answer. I want to prefix this by stating that I can't cheat for any of these challenges; with that I mean I can't look up any other implementations online. After the implementation, I will validate the answer by using this document or a similar sheet.

In this article I'll be solving: Project Euler #1.

This article features only an answer, because I’ve started writing from problem 14.

fn multiples_of_3_and_5(n: i32) -> i32 {
    let mut total: i32 = 0;
    for i in 0..n {
        if i % 3 == 0 || i % 5 == 0  {
            total += i

fn find_multiples_of_3_and_5() {
    assert_eq!(multiples_of_3_and_5(10), 23);
    assert_eq!(multiples_of_3_and_5(1000), 233168);

The full solution is available on GitHub.