---
id: 5900f4231000cf542c50ff34
challengeType: 5
title: 'Problem 181: Investigating in how many ways objects of two different colours can be grouped'
videoUrl: ''
localeTitle: 问题181：调查两种不同颜色的对象可以分组的方式
---

## Description
<section id="description">有三个黑色物体B和一个白色物体W它们可以用7种方式分组：（BBBW）（B，BBW）（B，B，BW）（B，B，B，W）（B，BB，W） （BBB，W）（BB，BW）在六十个黑色物体B和四十个白色物体W的分组方式中有多少种？ </section>

## Instructions
<section id="instructions">
</section>

## Tests
<section id='tests'>

```yml
tests:
  - text: <code>euler181()</code>应该返回83735848679360670。
    testString: 'assert.strictEqual(euler181(), 83735848679360670, "<code>euler181()</code> should return 83735848679360670.");'

```

</section>

## Challenge Seed
<section id='challengeSeed'>

<div id='js-seed'>

```js
function euler181() {
  // Good luck!
  return true;
}

euler181();

```

</div>



</section>

## Solution
<section id='solution'>

```js
// solution required
```
</section>
