Answer:
150 in³
Explanation:
We want to find half the volume of a rectangular pyramid. The volume of the whole pyramid is given by the formula ...
V = 1//3LWH
V = 1/3(5 in)(15 in)(12 in) = 300 in³
Then the volume of the half that is not filled with marbles is ...
1/2V = 1/2(300 in³) = 150 in³
150 cubic inches of marbles are needed to finish filling the container.