It took her 2 hours less to ride back to college on the bus than it took her to ride home on her bike, and the average speed of the bus was 10 miles per hour faster than Kayla’s biking speed. There ar...It took her 2 hours less to ride back to college on the bus than it took her to ride home on her bike, and the average speed of the bus was 10 miles per hour faster than Kayla’s biking speed. There are three quantities involved here – the time it would take each of the two people to do the job alone and the time it would take for them to do the job together. The jet goes 300 mph faster than the rate of the car, and the car ride takes 1 hour longer than the jet.