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**jacks****Member**- Registered: 2012-11-21
- Posts: 77

Consider all

non empty subsets of the set .For every subset we find the product of each of these elements.

Sum of all these products is?

*Last edited by jacks (2012-12-10 07:59:38)*

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 85,358

Hi;

I am getting (n+1)! - 1 but I do not know of a proof of that.

**In mathematics, you don't understand things. You just get used to them.Of course that result can be rigorously obtained, but who cares?Combinatorics is Algebra and Algebra is Combinatorics.**

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**scientia****Member**- Registered: 2009-11-13
- Posts: 222

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