SOLUTION: A bus service runs between two cities. Going one way, the average speed of the bus is 66 mph, and going the other way, it is 3 mph slower, so the ride takes 20 minutes longer. What

Algebra ->  Customizable Word Problem Solvers  -> Travel -> SOLUTION: A bus service runs between two cities. Going one way, the average speed of the bus is 66 mph, and going the other way, it is 3 mph slower, so the ride takes 20 minutes longer. What      Log On

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Question 232736: A bus service runs between two cities. Going one way, the average speed of the bus is 66 mph, and going the other way, it is 3 mph slower, so the ride takes 20 minutes longer. What is the distance between the two cities?
I have come up with this but I am not positive if its right:
Distance 66(x)and 63(x+20)
Rate 66 and 63
Time is x and x+20?

Found 2 solutions by rfer, josmiceli:
Answer by rfer(16322) About Me  (Show Source):
You can put this solution on YOUR website!
66x=63(x+1/3)
66x=63x+21
3x=21
x=7 miles
Don't mix minutes and hours
otherwise your setup looks good.

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Right idea, but the units for time all need to be the same. Call the trip back t+%2B+1%2F3
since 1%2F3+=+20%2F60 hrs
(1) d+=+66%2At
(2) d+=+63%2A%28t+%2B+1%2F3%29
This is 2 equations and 2 unknowns, so it should be solvable
d is the same in both, so set (1) = (2)
66t+=+63t+%2B+63%2F3
66t+=+63t+%2B+21
3t+=+21
t+=+7 hrs
and
(1) d+=+66%2At
d+=+66%2A7
d+=+462 mi
The distance between the cities is 462 mi
check:
(2) d+=+63%2A%28t+%2B+1%2F3%29
462+=+63%2A%287+%2B+1%2F3%29
462+=+63%2A%2822%2F3%29
1386+=+1386
OK