As the figure shows, a ball and cone are inscribed by a cyli

This topic has expert replies
User avatar
Elite Legendary Member
Posts: 3991
Joined: Fri Jul 24, 2015 2:28 am
Location: Las Vegas, USA
Thanked: 19 times
Followed by:37 members
[GMAT math practice question]

As the figure shows, a ball and cone are inscribed by a cylinder. What is the ratio of the volumes of the sphere to the cone to the cylinder?

Image

A. 1:1:2
B. 1.5:1:3
C. 1.5:1.5:2
D. 2:1:3
E. 3:2:4

User avatar
Elite Legendary Member
Posts: 3991
Joined: Fri Jul 24, 2015 2:28 am
Location: Las Vegas, USA
Thanked: 19 times
Followed by:37 members

by Max@Math Revolution » Wed Aug 07, 2019 1:57 am
=>

From the figure, the radii of the sphere and the base circle are (9/2).
The volume of the sphere is (4/3) π(9/2)^3 = π(243/2).
The volume of the cone is (1/3) π(9/2)^2(9) = π(243/4).
The volume of the cylinder is π(9/2)^2(9) = π(729/4)

Thus, the volumes are in the ratio π(243/2) : π(243/4) : π(729/4) = 2 : 1 : 3.

Therefore, the answer is D.
Answer: D