Each month, we will post a new Challenge Problem for you to attempt. If you submit the correct answer, you will be entered into that month’s drawing for a free Manhattan GMAT Prep item. Tell your friends to get out their scrap paper and start solving!

Note We email the winner directly every month, and provided we then receive consent from the winner we post his or her name on our Facebook Fan Page .

Good luck! These are tough problems!

This Month's Problem: "Mischa's Trip"

Mischa drove from A to B, a distance of 100 miles, at an average speed of 50 miles per hour, and then back from B to A along the same route at an average speed of m miles per hour.  What is the value of m?
 
(1) Mischa’s average speed for the entire round trip, excluding any time he spent at point B, was   miles per hour.
 
(2) If Mischa’s average speed from B to A had been 20% slower, the total time for the entire round trip, excluding any time Mischa spent at point B, would have been 12.5% greater.

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