Mathematics

Problem

A spherical snowball melts so that its surface area is decreasing at

20\text{ cm}^2\!/\text{min}

when its radius is

8\text{ cm}

. What is the corresponding rate of change of the volume at that instant? a)

-160\text{ cm}^3/\text{min}

80\text{ cm}^3/\text{min}

-80\text{ cm}^3/\text{min}

-20\text{ cm}^3/\text{min}