A cube is packed with decorative pebbles. If the cube has a side length of 2 inches, and each pebble weighs on average 0.5 lb per cubic inch, what is the total weight of the pebbles in the cube?

We can solve this problem by first solving for the total volume of the cube. The formula for volume of cube is given as:

V cube = s^3

Where s is the length of one side which is equivalent to 2 inches. Therefore:

V cube = (2 inches) ^3

V cube = 8 cubic inch

Assuming that all the pebble fills the cube without any spaces, then the total weight of the pebbles in the cube would simply be:

Total weight = 0.5 lb per cubic inch * 8 cubic inch

Total weight = 4 lb

Therefore, the total weight of the pebbles in the cube is 4 lbs.