A) A street light is mounted at the top of a 15 foot tall pole. A man 6 ft tall walks away from the pole with a speed of 5 ft/s along a straight path. How fast is the tip of his shadow moving when he is 40 ft from the pole?

B) Two cars start moving from the same point. One travels south at 60 mi/h and the other travels west at 25 mi/h. At what rate is the distance between the cars increasing three hours later?

C) At noon, ship A is 100 km west of ship B. Ship A is sailing south at 10 km/h and ship B is sailing north at 15 km/h. How fast is the distance between the ships changing at 3:00 PM?