What is the volume of this rectangular prism?

Jasper built a dollhouse for his younger sister.

A rectangular prism has a length of 24 inches, width of 8 inches, and height of 10 inches. A triangular prism has a triangular base of 24 inches and height of 6 inches. The height of the prism is 8 inches.
Which equation shows how to determine the volume of the dollhouse?
V = 24 (10) (8) + one-half (6) (24) (8)
V = 24 (10) (8) + one-third (6) (24) (8)
V = 24 (10) (8) + one-half (6) (24) (10)
V = 24 (10) (8) + one-third (6) (24) (10)