sum_of_factors.rb

class SumOfFactors
 
  def initialize(until_num, *divisible_by)
    @until_num = until_num
    @divisible_by = divisible_by
  end
 
  def get_sum
    get_range.collect { |num| num if divisible? num  }.compact.inject :+
  end
 
  private
 
  def divisible?(num)
    @divisible_by.any? {|div| num % div == 0 }
  end
 
  def get_range
    (1..@until_num)
  end
 
end
 
sum = SumOfFactors.new(100, 3, 5).get_sum
puts sum