6. A person who is 6 feet tail is walking away.r from a lamp post at the rate of 50 feet per minute. When the person is 15 feet from the lamp post, his shadow is 312) feet long. a. Find the rate at which the length of the shadow is inoreasing when he is 20 feet from the lamp post. b. Find the rate at which the tip of the shadow is increasing when he is 20 feet from the lamp post