A spherical balloon has a variable radius. The rate at which its volume is increasing with respect to its radius when radius is 5 cm is :
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → $100\pi \, cm^2$
$v=\frac{4}{3}πR^3$
so $\frac{dv}{dR}=4πR^2$
$\left.\frac{dv}{dR}\right]_{R=5}=100\pi \, cm^2$