This is a related rate problem. A man starts walking north at 4 ft/s from a point P. Five minutes later a woman starts walking south at 5 ft/s from a point 500 ft due east of P. At what rate are the people moving apart 15 min after the woman starts walking? I'm just trying to interpret it into the numbers and drawing a triangle. But I don't get a right equations for it. the answer is 837/ sqaure root of 8674 which is 8.99 ft/s Thank you so much.