---
id: 5900f4571000cf542c50ff6a
challengeType: 5
title: 'Problem 235: An Arithmetic Geometric sequence'
videoUrl: ''
localeTitle: 问题235：算术几何序列
---

## Description
<section id="description">给定是算术几何序列u（k）=（900-3k）rk-1。设s（n）=Σk= 1 ... nu（k）。 <p>找到r的值，其中s（5000）=  -  600,000,000,000。 </p><p>将您的答案四舍五入到小数点后面的12位。 </p></section>

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

## Tests
<section id='tests'>

```yml
tests:
  - text: <code>euler235()</code>应该返回1.002322108633。
    testString: 'assert.strictEqual(euler235(), 1.002322108633, "<code>euler235()</code> should return 1.002322108633.");'

```

</section>

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

<div id='js-seed'>

```js
function euler235() {
  // Good luck!
  return true;
}

euler235();

```

</div>



</section>

## Solution
<section id='solution'>

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