Add all the natural numbers below one thousand that are multiples of 3 or 5.

euler-001.rb

#!/usr/bin/env ruby

# Problem: Add all the natural numbers below one thousand that are multiples of 3 or 5.
# Description: 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.

sum = 0
limit = 1000 - 1

0.upto(limit) do |n|
  unless (n%3).zero? || (n%5).zero?
    next
  else
    sum += n
    puts sum if n == limit
  end
end