math
posted by jj .
a boy is blowing a spherical balloon at a rate of 50 cm3/s.at what rate is the radius of the balloon changing when the radius is 10 cm?give your answer to 2 decimal places.

I assume you do calculus.
V= 4/3 PI r^3
dV/dt= 4 PI r^2 dr/dt
you are given dV/dt= 50cm^3/s; find dr/dt