SOLUTION: A car travels from town a to town b going 30 mph, on the trip back, its averaging 45 mph? How far is it between towns if the whole trip took 9 hours?

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Question 676354: A car travels from town a to town b going 30 mph, on the trip back, its averaging 45 mph? How far is it between towns if the whole trip took 9 hours?
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
A car travels from town a to town b going 30 mph, on the trip back, its averaging 45 mph?
How far is it between towns if the whole trip took 9 hours?
:
Let d = dist from town a to b
:
Write a time equation, time = dist/speed
:
To time + return time = 9 hrs
d%2F30 + d%2F45 = 9
multiply by 90 to rid us of the denominators
3d + 2d = 90(9)
5d = 810
d = 162 miles from town a to b
:
:
Confirm this by finding the time each way
162/30 = 5.4 hrs
162/45 = 3.6 hrs
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total = 9 hrs