Two paramedics, Bob and Charlie, carry a 200 lb patient on an 8-foot-long stretcher. Bob holds the front end of the stretcher and Charlie holds the back end. The patient lies closer to the front end of the stretcher, so his center of gravity is 3 feet from Bob's hands and 5 feet from Charlie's. How much of the patient's weight is carried by Bob and how much by Charlie? where to start? what equation?