freeCodeCamp/curriculum/challenges/en/08-coding-interview-prep/project-euler/problem-239-twenty-two-foolish-primes.en.md

id, challengeType, title

id	challengeType	title
5900f45c1000cf542c50ff6e	5	Problem 239: Twenty-two Foolish Primes

Description

A set of disks numbered 1 through 100 are placed in a line in random order.

What is the probability that we have a partial derangement such that exactly 22 prime number discs are found away from their natural positions? (Any number of non-prime disks may also be found in or out of their natural positions.)

Give your answer rounded to 12 places behind the decimal point in the form 0.abcdefghijkl.

Instructions

Tests

- text: <code>euler239()</code> should return 0.001887854841.
  testString: 'assert.strictEqual(euler239(), 0.001887854841, ''<code>euler239()</code> should return 0.001887854841.'');'

Challenge Seed

function euler239() {
  // Good luck!
  return true;
}

euler239();

Solution

// solution required