Choose ONE of the following (a) A spherical balloon is inflated with gas at the rate of 700m cubic centimeters per minute. How fast is the radius of the balloon increasing at the instant the volume is 972m cubic centimeters? (Recall the volume of a sphere having radius r is far".) (b) A ladder 24 feet long is leaning against the wall of a house. The base of the ladder is pulled away from the wall at a rate of 3 feet per second. What is the velocity of the top of the ladder when the base is 9 feet away from the wall