data/problems/239.yml
---
:id: 239
:name: Twenty-two Foolish Primes
:url: https://projecteuler.net/problem=239
:content: "A set of disks numbered 1 through 100 are placed in a line in random order.\n\nWhat
is the probability that we have a partial derangement such that exactly 22 prime
number discs are found away from their natural positions? \n(Any number of non-prime
disks may also be found in or out of their natural positions.)\n\nGive your answer
rounded to 12 places behind the decimal point in the form 0.abcdefghijkl.\n\n"