If n is a positive integer and n^2 is divisible by 264, then the largest positive integer that must divide n is	Choose the correct option:
A) 6
B) 12
C) 24
D) 36
E) 48
The question asks aboutthe largest positive integer that MUST divide n, not COULD divide n. Since the least value of n for which n^2 is a multiple of 72 is 12 then the largest positive integer that MUST divide n is 12.   Complete solution of this question is given above. Please ask if anything remains unclear.   I spent a few hours on this one alone and I'm still not clear. I chose 12 at first, but then changed to 48.   I'm not a native speaker, so here is how I interpreted this question:the largest positive integer that must divide n=the largest positive factor of n. Since n is a variable (i.e. n is moving), so is its largest factor. Please correct if I'm wrong here.   I know that if n = 12, n^2 = 144 = 2 * 72 (satisfy the condition). When n = 12, the largest factor of n is n itself, which is 12. Check: 12 is the largest positive number that must divide 12 --&gt; true   However if n = 48, n^2 = 48 * 48 = 32 * 72 (satisfy the condition too). When n = 48, the largest factor of n is n itself, which is 48. Check: 48 is the largest positive number that must divide 48 --&gt; true   So, I also notice that the keyword isMUST, notCOULD. The question is, why is 48 notMUST divide 48, but instead onlyCOULD divide 48? I'm not clear right here. Why is 12MUST divide 12? What's the difference between them?   Only restriction we have on positive integer n is that n^2 is divisible by 72. The least value of n for which n^2 is divisible by 72 is 12, thus nmustbe divisible by 12 (n is in any case divisible by 12). For all other values of n, for which n^2 is divisible by 72, n will still be divisible by 12. This means that n is always divisible by 12 if n^2 is divisible by 72.   Now, ask yourself: if n=48, is n divisible by 48? No. So, n is not always divisible by 48.   48
<result>E</result>
If n is a positive integer and n^2 is divisible by 264, then the largest positive integer that must divide n is