Prime factorization is unique except for the order of factors.
n could only be 3 because
(q^3*p^2)/r^2 = s^n
then
q^3*p^2= r^2*s^n
There are 5 primes multiplied together on the left, so
there must the same 5 primes multiplied together on the right.
In fact p=r and q=s, and of course n=3.
Edwin