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Guest Message by DevFuse

Three cars

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Posted 26 July 2014 - 05:27 AM

There are three cars driving on a track.  The track is a perfect circle (circumference unknown) and is not wide enough to allow any car to pass another.  Currently, the lead car is going 55 MPH and the last car is going 45 MPH.  While the car in the middle is going some speed between.  At this moment there is x miles between the lead car and the middle car and x miles between the middle car and the slowest car where x is not 0 or 1 miles.  If the car's maintained their speed up to the point where the lead car caught the slowest car (then everyone stops), would there ever be a point and time where the distance between any two pairs is again x miles (the pairs must be x distance apart at the same time)?

Edited by BMAD, 26 July 2014 - 05:28 AM.

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#2 JIntorcio

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Posted 26 July 2014 - 06:20 AM

Is this solvable without knowing circumfrence?

Edited by JIntorcio, 26 July 2014 - 06:22 AM.

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#3 bonanova

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Posted 26 July 2014 - 08:35 AM

Agree with JIntorcio.

The restriction that x is not 1 mile is innocuous, since that value has no inferable relation to the length of the track.

A standard approach with an unspecified parameter is to assign it a value, say 10 in this case, inferring that the answer does not depend on the value. (else it would be given.) Best example of this is the hole-in-the-sphere problem.
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#4 wolfgang

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Posted 26 July 2014 - 08:57 AM   Best Answer

Spoiler for No....

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#5 plasmid

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Posted 27 July 2014 - 05:41 AM

Spoiler for Unless...

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Posted 28 July 2014 - 12:09 PM

Fair point
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