A person takes a trip, driving with a constant speed of 89.5km/h, except for a 22 min rest stop. If the person average velocity is 77.8km/h, how much time is spent on the trip and how far does the person travel.

I've tried to solve it but can't seem to grasp it, if some one can give me the equation or a way to solve this please help.

Question

A person takes a trip, driving with a constant speed of 89.5km/h, except for a 22 min rest stop. If the person average velocity is 77.8km/h, how much time is spent on the trip and how far does the person travel. 

I've tried to solve it but can't seem to grasp it, if some one can give me the equation or a way to solve this please help.

anonymous · Answer

The expression for the average velocity is x/t, since the stop changed the average velocity by changing the time spent on the trip, we only neet to take that time off to get a second equation to solve the system:
x/(t-22/60)=89.5
x/t=77.8