A Spherical balloon is being inflated.
Find a general formula for the instantaneous rate of change of the volume $\>V\>$ with respect to the radius $\>r$, given that $\>V = \frac{4\pi r^{3}}{3}\>$.

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Find the rate of change of $\>V\>$ with respect to $\>r\>$ at the instant when the radius is $\>r = 5$.

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