GMATprep: of the following, which is greatest?

[nhai2003]

of the following, which is greatest?
A. (1/5)^-2 ( I thought (1/5^-2 = 1/1/5^2 = 1x5^2/2 = 25????)
B. (1/3)^-2
C. 3^-2
D. 5^-2
E. 2^3

I thought D
but OA
A

[ssmiles08]

anytime you have a negative power like the question above...you take the reciprocal of the number.

so (A) has (1/5)^-2 = 5^2

similarly the case with B. it becomes 3^2.

C, and D become fractions b/c of the negative powers.

E = 8, but is still less than A which is 25.

(A)

[nhai2003]

sorry I mistook "greatest" with "smallest".
Now I understand why.
Thanks Ssmile!