Question

Sarah leaves Seattle for New York in her car, averaging 80 mph across open country. One hour later a plane leaves Seattle for New York following the same route and flying 400 mph. How long will it be before the plane overtakes the car?

Answer 1

well, if we start them off together at their relative starting points:

S = 80h + 80(1) since she is already 1 hour ahead

A = 400h + 400(0); since it hasnt gone anywhere at the start

when S=A then they are at the same point at the same time