Well, let's see.
Perfect cubes that are two digits:
27
64
Could it be 27? Well, 2+7 is 9, and that's a perfect square with a square root of 3, and the cube root of 27 is three.
Looks like we've found our answer, especially since 6+4 = 10, which is NOT a perfect square.
27
27. Here you just have to plug stuff in until it works. That's my philosophy.
729, cube of 9 and square of 27
729
6
27
4
27, whose cube is 19683
27. Here you just have to plug stuff in until it works. That's my philosophy.
729, cube of 9 and square of 27
6859
1
It is: 1,000,000
729
729
6
7 * * * * * What? 73 = 343 which is the square of 18.52... hardly a perfect square! The correct answer is 9.