If the radius of a cylinder is made 3 times and height is doubled, what is the new volume of the cylinder divided by the old one?	Pick one
A) 18 .  B) 2 .  C) 6 .  D) 4 .  E) 10 .

Rationale: let v and v ' be the original and the changed volume now v = pir ^ 2 h v ' = pi ( 3 r ) ^ 2 ( 2 h ) v ' = 18 v a ) 18
Answer: A