In a Classical Equation from Chemistry, the Pressure of a Gas

Multiple Choice

In a classical equation from chemistry, the pressure of a gas is proportional to the product of the volume of the gas and the temperature of the gas. In symbols, P = kVT for some constant k. How fast is the pressure changing at an instant when the volume is 20 mL and increasing at 3 mL/min and the temperature is at 21 degrees C and is decreasing at a rate of 2 degrees per minute? Assume that k = 0.8 kilograms per mL-degree.

A) increasing at 18.4 kilograms/min
B) increasing at 14.4 kilograms/min
C) decreasing at 23.5 kilograms/min
D) decreasing at 12.8 kilograms/min
E) increasing at 12.7 kilograms/min