sum_of_multiples.rb

class SumOfMultiples

  attr_accessor :args

  def initialize *args
    self.args = args
  end

  def self.to n
    new(3,5).to n
  end

  def to n
    sum = 0
    n.times do |x|
      sum += x if is_divisible? x
    end
    sum
  end

  def is_divisible? x
    args.any? { |m| x % m == 0 }
  end

end