Volume of a rectangular prism is V = L x W x H
The length for the small prism is 6
The width for the small prism is 4
The height for the small prism is 3
So 6 x 4 x 3 = 72
The length for the large prism is 16
The width for the large prism is 9
The height for the large prism is 2
So 16 x 9 x 2 = 288
Now you add the two volumes together: 288 + 72 = 360 ft cubed.