Today I solved this algorithm that is the third problem in Project Euler.

This still need some improvement, because even when the last prime number is found it still counts and takes a really long time when given big numbers.

require 'prime' def largestPrime(num) result = 0 (2...num).each do |i| result = i if (num % i) == 0 && i.prime? end puts result end largestPrime(13195)

I will update this code as soon as I find a better solution but for now it works.