Wednesday, March 11, 2009

Escalator greetings.

Two Escalators are moving parallel to each other. One up and one down. Each has 100 stairs. One person stands on every stair and new people keep coming up as escalator moves and new stairs appear. You are stepping on the bottom stair of the escalator that goes up. How many people will you meet along your ride up?


Anonymous said...

200. By the time you reach the middle of the escalator so will the guy on the opposite escalator which means you'll meet 100, and then you double it. Alina

Maria said...

You did it!
My father, who suggested this puzzle, also agrees with this solution. However, I do recollect seeing a 199 answer in one of the books with explanation that you do not really meet two people on your last segment. But I think you are right with 200 answer, unless someone clearly proves otherwise below :)

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