OG - Quant Review PS - #163

by **mrkamal** Sat Jul 28, 2007 7:21 pm

Hi,
I don't understand the answer explanation for PS Q #163 from pg 83 of the OG Quant Review book. The question is:

8^2 x 3^3 x 2^4
---------------------
96^2

A) 3
B) 6
C) 2
D) 12
E) 18

I got the answer (A) correct by doing all the math, but I know that's inefficient. The explanation given matter of factly tells you to simplify the expression 96^2 to 8^2 x 3^2 x 2^4. I don't understand how it goes from one to the other, in other words, what is the process for doing this simplification?
Thanks

by **givemeanid** Sun Jul 29, 2007 12:03 am

96^2
= (8*12)^2
= (8*3*4)^2
= 8^2 * 3^2 * 4^2 --> (xy)^n = x^n * y^n
= 8^2 * 3^2 * (2^2)^2
= 8^2 * 3^2 * 2^4 --> (x^r)^s = x^(rs)

by **dbernst** Sun Jul 29, 2007 8:43 am

givemeanid,

thanks for the clear explanation!

by **mrkamal** Mon Jul 30, 2007 2:17 pm

Thanks a lot! Makes sense now.