1. The problem statement, all variables and given/known data I have a homework assignment that I find challenging A spherical baloon is being inflated at a rate of 10 cu.in/sec (i assume it's cubic inches per second) Find the rate of change of area when the baloon has radius=6 2. Relevant equations So far I know that V=(4/3)*pi*r^3 A=4*pi*r^2 dV/dt = 10 in^3/sec So the question is, how do I find dA/dt when radius=6 and the volume increases at a rate of 10 in^3/sec ? I'm realyl stuck here. Can someone help? 3. The attempt at a solution I've just been wild guessing here. I know that dV/dt= 4*pi*r*dr/dt and that dV/dt=10, but if i substitute it into 10= 4*pi*r*dr/dt and isolate dr/dt, I don't really get anywhere. The answer is supposed to be 10/3 in^2 sec.