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MathNet 2006 — Part 05 Question 22

Math Olympiad Vault · MathNet 2006 — Part 05

Question 22

Six people, all of different weights, are trying to build a human pyramid: that is, they get into the formation

> A
> B C
> D E F

We say that someone not in the bottom row is "supported by" each of the two closest people beneath her or him. How many different pyramids are possible, if nobody can be supported by anybody of lower weight?