Answer:
384
Explanation:
First find the volume of Janet's box (or rectangular prism) by using the formula l*w*h. Plug in the values and you'll get 4*6*8 (order doesn't matter in this equation). So you can start multiplying anywhere so do 4*6 which is 24, then do 24*8 which is 192.
Now that you found the the volume of Janet's box multiply 192 by 2 since Gary's box is TWICE the volume of Janet's. 192*2=384.