Question

A bus leaves the school traveling west at 50 miles per hours. After it travels 15 miles, a car follows the bus, traveling at 55 miles per hour. After how many hours will the car catch up with the bus? Let t = time in hours, and let d = distance in miles.

Answer 1

3 hours

Explanation:

The rate of bus is 50

The rate of car is 55

Which means, per hour, the Car catches up by 55 - 50 = 5 miles

Since, the car starts AFTER the bus has already travelled 15 miles, the CAR IS BEHIND by 15 miles. To catch up these 15 miles (at the rate of catching up 5 miles per hour), the car would need:

15/5 = 3 hours to catch up with the BUS

Note: we use the formula

d = rt

where d = distance

r is rate

t is time

Thus, we had:

d = rt

t = d/r

t = 15/5

t = 3

Thus, after 3 hours, the car with catch up with the bus