---
id: 5900f4a01000cf542c50ffb2
challengeType: 5
title: 'Problem 307: Chip Defects'
---

## Description
<section id='description'>
k defects are randomly distributed amongst n integrated-circuit chips produced by a factory (any number of defects may be found on a chip and each defect is independent of the other defects).


Let p(k,n) represent the probability that there is a chip with at least 3 defects.
For instance p(3,7) ≈ 0.0204081633.


Find p(20 000, 1 000 000) and give your answer rounded to 10 decimal places in the form 0.abcdefghij
</section>

## Instructions
<section id='instructions'>

</section>

## Tests
<section id='tests'>

```yml
tests:
  - text: <code>euler307()</code> should return 0.7311720251.
    testString: assert.strictEqual(euler307(), 0.7311720251, '<code>euler307()</code> should return 0.7311720251.');

```

</section>

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

<div id='js-seed'>

```js
function euler307() {
  // Good luck!
  return true;
}

euler307();
```

</div>



</section>

## Solution
<section id='solution'>

```js
// solution required
```

</section>