Multiples of 3 and 5


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.

  
    function myFunction() {
    const reducer = (number, total) => number + total;

    var a = [];
    for (i = 0; i < 1000; i++)
      if (i % 3 == 0 || i % 5 == 0) {
        a.push(i);
      }
    document.getElementById("answer").innerHTML = a.reduce(reducer);
  }

Check it out on codepen