The Radius, R, of a Sphere Is Increasing $\frac { \mathrm { dV } } { \mathrm { dt } }$

Short Answer

The radius, r, of a sphere is increasing. For what value of r is $\frac { \mathrm { dV } } { \mathrm { dt } }$ equal to 64π times the rate of increase of r. Enter just an integer.