40.Twenty Horses, Five Lanes
★★★puzzlesIMC Trading
You have 20 horses and a track that races 5 at a time, reporting only finishing order. Every horse runs at a consistent speed and there are no ties. What is the minimum number of races needed to identify the fastest three in order?
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Four group races plus a race of the winners narrows things down. Then count how many horses are still genuinely in contention for second and third.
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