Distance, Time, and Speed problem

Question

John traveled from Town A to Town B at a rate of 55 mph. Traffic was bad on his return trip home, and he traveled at a rate of 45 mph, so it took him an hour longer. How long did it take him to drive the entire trip?

The answer is 10 hours but I don't know how...

Answer 1

Use the standard formula of rate * time = distance and make the chart.

 

                                rate                 time                  distance

going                      55                      x                           55x

returning                 45                      x+1                      45(x+1)

 

Now since going and returning ( assuming that he took the same route home!!!) must be the same distances, so

 

55x = 45(x+1)

55x = 45x + 45

10x = 45

x     = 4.5 hours

 

Plug back into the chart and going took 4.5 hours while returning took 5.5 hours, so together, he drove 10 hours.

 

Hope this helped.