A perfect square is defined as the square of an integer and a perfect cube is defined as the cube of an integer. How many positive integers n are there such that n is less than 30,000 and at the same time n is a perfect square and a perfect cube? Select the correct option:
A) 4
B) 5
C) 6
D) 7
E) 8
If n is a perfect square and a perfect cube, then n = a^6 for some integer a.   The numbers are 1^6=1, 2^6=64, 3^6= 729, 4^6=4096, 5^6=15,625.   The answer is 5.
<result>B</result>
A perfect square is defined as the square of an integer and a perfect cube is defined as the cube of an integer. How many positive integers n are there such that n is less than 30,000 and at the same time n is a perfect square and a perfect cube?