Acube is packed with decorative pebbles. if the cube has a side length of 6 inches, and each pebble weighs on average 0.5 lb per cubic inch, what is the total weight of the pebbles in the cube?

First we have to calculate the volume of the cube:
V = l³ ,  where l = 6 in
V = 6³ = 216 in³
Each pebble weights on average is 0.5 lb per cubic inch.
Weight = 216 in³ · 0.5 lb/in = 108 lb

The total weight of the pebbles in the cube is 108 lb.