If s is a positive integer, what is the value of s?

Question

(1) s=r^3, where r is an integer.
(2) s=t^2, where t is an integer.

Charli08 · Answer

(1) s=r^3, where r is an integer.
(2) s=t^2, where t is an integer.

Each of the statements alone is clearly insufficient, so lets consider them combined.

The first values to consider are:
 r = 1 & t = -1 ==> s = 1.

I think here is where most people make the mistake to stop. However there is at least one more case:

r = 4 & t = 8 ==> s = 64

==>  E.

Prep Toolkit