lets assume height as x
so width will be 2x
and length will be 3x similarly.
so,
Volume of prism = w * h * l
384 = 2x * x * 3x
384 = 6x^3
dividing both sides by 6
64 = x^3 ( taking cube root of 64)
4 = x
So,
Height = 4
width = 4 * 2 = 8
length = 4 * 3 = 12
Hope this helps.. :)