The volume V of a pyramid varies jointly as its height h and the area of its base B . Given that the volume of the pyramid is 60 cubic inches when the height is 5 inches and area of its base is 36 square inches, what is the area of the base if its volume is doubled and the height is halved?

Answer 1

V = kBh
B = V/kh

Now you just find B' where

B' = V'/kh' = (2V)/(k*h/2) = 4V/kh = 4B = 4*36 = 144