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Maykop and Belorechensk

Source: All-Russian 2007

May 4, 2007
combinatorics unsolvedcombinatorics

Problem Statement

The distance between Maykop and Belorechensk is 2424 km. Two of three friends need to reach Belorechensk from Maykop and another friend wants to reach Maykop from Belorechensk. They have only one bike, which is initially in Maykop. Each guy may go on foot (with velocity at most 66 kmph) or on a bike (with velocity at most 1818 kmph). It is forbidden to leave a bike on a road. Prove that all of them may achieve their goals after 22 hours 4040 minutes. (Only one guy may seat on the bike simultaneously).
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