SOLUTION: A motorist starts from city A at 2:00 P.M. and travels to city B at an average speed of 30 miles/hour. After resting at B for one hour, he returns over the same route at an average
Question 667749: A motorist starts from city A at 2:00 P.M. and travels to city B at an average speed of 30 miles/hour. After resting at B for one hour, he returns over the same route at an average speed of 40 miles/hour and arrives at A that evening at 6:30 P.M. Determine the distance between A and B. Answer by ankor@dixie-net.com(22740) (Show Source):
You can put this solution on YOUR website! A motorist starts from city A at 2:00 P.M. and travels to city B at an average speed of 30 miles/hour.
After resting at B for one hour, he returns over the same route at an average
speed of 40 miles/hour and arrives at A that evening at 6:30 P.M.
Determine the distance between A and B.
:
let d = distance from A to B
:
From the information given, we know the total time from 2:00 to 6:30 = 4.5 hrs
However, the total travel time was 1 hr less; 3.5 hrs
:
Write a time equation; time = dist/speed
:
To time + return time = 3.5 hrs + = 3.5
multiply by 120, to clear the denominators, results:
4d + 3d = 120(3.5)
7d = 420
d = 420/7
d = 60 mi from A to B
:
:
Confirm this by finding the time each way
60/30 = 2 hrs
60/40 = 1.5 hrs
---------------
total time 3.5 hrs
