Two similar pyramids have lateral areas 20ft2 and 45ft2. The volume of the smaller pyramid is 8ft3.

What is the volume of the larger pyramid?

A) 27ft3

B) 18ft3

C) 36ft3

D) 9ft3

Let the ratio between 2 of them be a/b. The volume of the larger one is x (ft^3)

(a/b) ^2 = 20/45 = 4/9 - - - > a/b = 2/3

(a/b) ^3 = 8/x

8/x = (2/3) ^3 = 8/27 - - - > x = 27 (ft^3)