SOLUTION: help me set up this world problem: John left willie house driving toward the mountains one hour before Wilbur. Wilbur drove in the opposite direction going 12 km/h slower than

Question 1093232: help me set up this world problem:
John left willie house driving toward the mountains one hour before Wilbur. Wilbur drove in the opposite direction going 12 km/h slower than john for one hour after which time there were 159 km apart. Find johns speed.

Found 3 solutions by ikleyn, josmiceli, greenestamps:
Answer by ikleyn(52810)   (Show Source): You can put this solution on YOUR website!
.

Let J be john's speed, in km/h. Then the Wilbur' speed is J-12 km/h. In one hour John covered J kilometers, while Wilbour covered J-12 kilometers in opposite direction. Hence, the distance between them in one hour is J + (J-12) = 2J-12. From the other side, it is 159 km, according to the solution. It gives you an equation 2J - 12 = 159. The set up is completed.

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To see many other samples, examples and solved problems of this kind, look into the lessons
    - Travel and Distance problems
    - Travel and Distance problems for two bodies moving in opposite directions
    - Travel and Distance problems for two bodies moving in the same direction (catching up)
in this site.

Answer by josmiceli(19441)   (Show Source): You can put this solution on YOUR website!
First find John's head start in terms of miles
Let = John's speed in mi/hr

------------------------
Start a stop watch when Wilbur leaves.
It will stop in 1 hr
Let = the distance in miles Wilbur travels
in the 1 hr on the stop watch
Wilbur's equation:
(1)
John's equation:
(2)
-----------------------------
(2)
(2)
(2)
and
(1)
------------------------
Set (1) = (2)

John's speed is 57 mi/hr
------------------------
check answer:
(1)
(1)
(1) mi
and
(2)
(2)
(2)
(2) mi
OK

Answer by greenestamps(13203)   (Show Source): You can put this solution on YOUR website!

The first solution posted overlooked the fact that John traveled for 2 hours and Wilbur for only one hour. Other than that, it is a simpler approach than used in the second response.

Correcting the oversight in the first response, we have
John traveling for 2 hours at speed x;
Wilbur traveling for 1 hour at speed x-12; and
at the end they are 159 miles apart. So

And, as was said in the first response, you should be able to finish from there.
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