project_euler/1.rb
Code:
# Project Euler Problem 1: Multiples of 3 or 5
# https://projecteuler.net/problem=1
# 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.
def solve(n)
(1...n).filter { |m| m % 3 == 0 || m % 5 == 0 }.sum
end
puts solve(10)
puts solve(1000)Output:
23
233168