Hello,
I’m super new to Gregmat and have just begun with the two month schedule. Had two queries:

There was a small homework question on ‘How many zeroes are there at the end of 25!?’
Query: Is it a correct approach to figure out the number 5’s in the prime factorization? Is the final answer two? 
In the things to do, under week 1 class 1, I didn’t completely understand the solution to the last problem  ‘S be the set of all positive integers n such that such that n^2 is a multiple of both 24 and 108…’
Query: Why did we consider only 2^3 for checking the divisibility of 24 and 3^2 for 108?
Thanks for your patience and time!