Write a program that, given a number, can find the sum of all the multiples of particular numbers up to but not including that number.
If we list all the natural numbers up to but not including 20 that are multiples of either 3 or 5, we get 3, 5, 6 and 9, 10, 12, 15, and 18.
The sum of these multiples is 78.
Write a program that can find the sum of the multiples of a given set of numbers. If no set of numbers is given, default to 3 and 5.
For installation and learning resources, refer to the exercism help page.
For running the tests provided, you will need the Minitest gem. Open a terminal window and run the following command to install minitest:
gem install minitest
If you would like color output, you can require 'minitest/pride' in
the test file, or note the alternative instruction, below, for running
the test file.
In order to run the test, you can run the test file from the exercise
directory. For example, if the test suite is called
hello_world_test.rb, you can run the following command:
ruby hello_world_test.rb
To include color from the command line:
ruby -rminitest/pride hello_world_test.rb
The test files may have the execution bit set so you may also be able to run it like this:
./hello_world_test.rb
A variation on Problem 1 at Project Euler view source