Question 1: Car A began a journey from a point at 9 am, traveling at 30 mph. At 10 am car B started traveling from the same point at 40 mph in the same direction as car A. At what time will car B pass car A?

Solution:

Let after t hours the distances D1 traveled by car A


=> D1 = 30 t


Car B starts at 10 am and will therefore have spent one hour less than car A when it passes it.


After (t - 1) hours, distance D2 traveled by car B


=> D2 = 40 (t - 1)


When car B passes car A, they are at the same distance from the starting point and therefore D1 = D2


=> 30 t = 40 (t - 1)


Solve the equation for t,