#!/usr/bin/ruby require "rational" def p1 p (0...1000).select {|i|i%3==0||i%5==0}.inject(0) {|a,b|a+b} end def p2 a,b = 1,1 sum = 0 while b<=4000000 sum += b if b%2==0 a,b = b,a+b end p sum end def p3 a=600851475143;(2..a).each{|i|i