# Sum Of Multiples

Given a number, find the sum of all the unique multiples of particular numbers up to
but not including that number.

If we list all the natural numbers below 20 that are multiples of 3 or 5,
we get 3, 5, 6, 9, 10, 12, 15, and 18.

The sum of these multiples is 78.

## Installation
See [this guide](https://github.com/exercism/xr/blob/master/docs/INSTALLATION.md) for instructions on how to setup your local R environment.

## How to implement your solution
In each problem folder, there is a file named `<exercise_name>.R` containing a function that returns a `NULL` value. Place your implementation inside the body of the function.

## How to run tests
Inside of RStudio, simply execute the `test_<exercise_name>.R` script. This can be conveniently done with [testthat's `auto_test` function](https://www.rdocumentation.org/packages/testthat/topics/auto_test). Because exercism code and tests are in the same folder, use this same path for both  `code_path` and `test_path` parameters. On the command-line, you can also run `Rscript test_<exercise_name>.R`.

## Source

A variation on Problem 1 at Project Euler [http://projecteuler.net/problem=1](http://projecteuler.net/problem=1)

## Submitting Incomplete Solutions
It's possible to submit an incomplete solution so you can see how others have completed the exercise.