JEE Main 201910 Apr, Evening shiftMathematicsMediumLimit, Continuity and Differentiability420× since 2002
A spherical iron ball of radius 10 cm is coated with a layer of ice of uniform thickness that melts at a rate of
50 cm³
/min. When the thickness of the ice is 5 cm, then the rate at which the thickness (in cm/min) of the ice
decreases, is :