Problem of the Week 7-23-19: Shaking Hands at a Party [Combinatorics]

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Solution below.

Problem of the Week: 12-06-18: Math Test [Combinatorics]

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Solution:

Video:

Combinatoric Identities

Here are a couple neat combinatorial identities.

Problem of the Week 2-20-18: Set Painting [Set Theory]

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Problem of the Week 1-23-18: Combinatorial Sum [Algebra,Combinatorics]

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Advanced Knowledge Problem of the Week

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Solution below the break.