Question 10 (1 point) A football shaped snowball melts such that it maintains its shape. Its volume is decreasing at the rate of 96cm / hour. What is the rate of change of its surface area, dSA/dt (in em?/hour) when r - 2 cm? The formula for the volume of a football is V = gar . The formula for the surface area of a football is SA - 8mr2. a) -16 b) -72 c) -72T d) -547 e ) - 12 f) None of (a) through (e) are correctQuestion 12 (1 point) Using the exponential decay formula as per lab 6, a drug is administered every few hours in regular dose sizes. The drug is neutralized at an exponential rate with a decay rate constant k hr-1. Not all of the drug is neutralized before the next dose is administered. Denote by A(t) the amount of drug in the patient's system at time & hours. Suppose that the eventual maximum residual drug level is 15-83. The closed form of the series representation of the residual drug level (for n doses) is: a -03-1 b) 03=1 c) ell-(e-0.3)- 1.3 d) 03-1 e) ee-0.3 [1-(C-05 m f) None of (a) through (e) are correct