D is your answer if you times 8 and 2 together to get your A& B
Use similar volume to calculate
which is the (ratio of edges)^3 = (ration of volume)
so just put the numbers in, let the volume of smaller pyramid be y.
(3/4)^3 = y/320
27/64 = y/320
y=135in3
How unspecific? What's the cost of one
Vi = 56
Vf = 56 + 7(3) = 56 + 21 = 77
THe average is (Vf + Vi)/2
(77 + 56)/2 = 133/2 = 66.5 m/s