Find the lcm of 36, 84, and 225.
Try doing the prime factorization for each, then multiply the values you get.
--If you get stuck: This video will help, try watching it :)
https://www.khanacademy.org/math/pre-algebra/pre-algebra-factors-multiples/pre-algebra-prime-factorization-prealg/v/prime-factorization