Question

How does the volume of a cylinder change if the radius is quadrupled and the height is reduced to a third of its original size?

A. v= 1/3 pie r^2 *h
B. v= 2/3 pie r^2 * h
C. v= 4/3 pie r^2 * h
D. v= 16/3 pie r^2 * h

Answer 1

Oh yay, proportional thinking! (Vicious sarcasm). Alright, let's do this:

Volume of the cylinder = π(h)r^2
New volume = π(h/3)(4r)^2
= (1/3)π(h)(16r^2)
=16*(1/3)π(h)r^2
=(16/3)π(h)r^2

Therefore, it's D. Though it's spelled pi, and you should really use the ^ symbol.