1#2520 is the smallest number that can be divided by each of the numbers from 1 to 10 without any remainder.
 2
 3#What is the smallest positive number that is evenly divisible by all of the numbers from 1 to 20?
 4describe "problem five" do
 5  def divisible_by?(number)
 6    return number % 2 == 0 &&
 7      number % 3 == 0 &&
 8      number % 4 == 0 &&
 9      number % 5 == 0 &&
10      number % 6 == 0 &&
11      number % 7 == 0 &&
12      number % 8 == 0 &&
13      number % 9 == 0 &&
14      number % 10 == 0 &&
15      number % 11 == 0 &&
16      number % 12 == 0 &&
17      number % 13 == 0 &&
18      number % 14 == 0 &&
19      number % 15 == 0 &&
20      number % 16 == 0 &&
21      number % 17 == 0 &&
22      number % 18 == 0 &&
23      number % 19 == 0 &&
24      number % 20 == 0
25  end
26
27  def smallest
28    n = 20
29    loop do
30      return n if divisible_by?(n)
31      n = n + 20
32    end
33  end
34
35  it 'produces the answer' do
36    expect(smallest).to eql(232792560)
37  end
38end