# 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 sumOfMultiplesLessThan(number)
          sum = 0
          (1..(number-1)).each { |x| sum += x if(x % 3 === 0 || x % 5 === 0) }
          sum
        end

        puts sumOfMultiplesLessThan(1000) 

        # Output:
        # 233168


        #Spec file
        require "problem1"

        describe "Multiples of 3 and 5" do
          describe "#sumOfMultiplesLessThan" do
            it "finds sum of all multiples 3 and 5 below 10" do
              sumOfMultiplesLessThan(10).should == 23
            end
          end
        end