Surface area of a cube: L^2 x 6
L^2 x 6 = 600
L^2 = 600 (division symbol) 6
L = (square root symbol) 100
L = 10
So the length of the square is 10, since it's a cube it means that all sides are the same length and to find the volume you need to times length by width by height.
10 x 10 x 10 = 1000cm^3
The volume of the cube is 1000cm^3
Hope this helps