freeCodeCamp/curriculum/challenges/chinese/10-coding-interview-prep/project-euler/problem-231-the-prime-factorisation-of-binomial-coefficients.md

---
id: 5900f4531000cf542c50ff66
title: 'Problem 231: The prime factorisation of binomial coefficients'
challengeType: 5
forumTopicId: 301875
dashedName: problem-231-the-prime-factorisation-of-binomial-coefficients
---

# --description--

The binomial coefficient 10C3 = 120.

120 = 23 × 3 × 5 = 2 × 2 × 2 × 3 × 5, and 2 + 2 + 2 + 3 + 5 = 14.

So the sum of the terms in the prime factorisation of 10C3 is 14.

Find the sum of the terms in the prime factorisation of 20000000C15000000.

# --hints--

`euler231()` should return 7526965179680.

```js
assert.strictEqual(euler231(), 7526965179680);
```

# --seed--

## --seed-contents--

```js
function euler231() {

  return true;
}

euler231();
```

# --solutions--

```js
// solution required
```