heman wrote:

If n is a positive integer and n^2 is divisible by 72, then the largest possible positive integer that must divide n is

A)6

B)12

C)24

D)36

E)48

I am confused what is being asked here.

Please explain your answers

Thanks

Heman

Folks, let me give a generalised answers to questions like these. Once we know the basic way to answer questions like these as

yezz said we can get that 700+

Concentrate for the next 5 minutes pleaseeeeeeee

given that n^2 is divisible by 72

So n^2 = 72xk (which means 72xk must be perfect squares)

n^2 = 9x4x2xk

Clearly 9 and 4 are perfect squares. So k must be minimum 2 to make the entire number a perfect square.

SO the general form of the k will be 2 x any perfect square.

ie k = 2x p^2

So n^2 = 9x4x2x2xp^2

hence n = 3x2x2xp

So the general value of n will 12xp, which must be divisible by12

I think i am lucid,

Regards,

_________________

Averages Accelerated:Guide to solve Averages Quickly(with 10 practice problems)