A Solid Is Formed by Adjoining Two Hemispheres to the Ends

Multiple Choice

A solid is formed by adjoining two hemispheres to the ends of a right circular cylinder. The total volume of the solid is 30 cubic centimeters. Find the radius, r, of the cylinder that Produces the minimum surface area. Round your answer to two decimal places.

A) $r \approx 2.68 \mathrm {~cm}$
B) $r \approx 2.39 \mathrm {~cm}$
C) $r \approx 1.93 \mathrm {~cm}$
D) $r \approx 3.57 \mathrm {~cm}$
E) $r \approx 2.52 \mathrm {~cm}$