The volume of a box with a square base is 54 cubic centimeters. If the height of the box is twice the width of the base, what is the height, in centimeters?
(D) 6

Box is cube

volume of cube = L * B * H
Since, base of the box is square L = B
From question, we know that H = 2 * B

If L = B = x
=> H = 2 * x

volume = L * B * H
= x * x * (2*x)
= 2 * x^3

Since , volume is 54 cubic centimeters

54 = 2 * x^3

54/2 = x ^ 3

27 = x ^ 3

=> x =3

Since, Height = 2 * B ( B = x = 3)
= 2 * 3 = 6

You could also factor 54 to

2 * 3 * 3 * 3

If the base is a square (equal length by length, or 3 * 3) the remaining multiple (and answer) is 6.