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  Discussion about math, puzzles, games and fun.   Useful symbols: √ ∞ ≠ ≤ ≥ ≈ ⇒ ∈ Δ θ ∴ ∑ ∫ π -

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Topic review (newest first)

John E. Franklin
2005-09-15 16:59:30

Well for starters, I see it is true for this example:
n=3 and r =2
sets are {1,2}, {1,3}, and {2,3}. 
So average of smaller in each pair is (1 + 1 + 2)/3
I'll try more later...

Alfie
2005-09-12 04:48:03

We have a set 1, 2, 3, ..., n. Consider all the r-element subsets of
this set. Prove that if we take the smallest element of each of these
subsets, the average of these smallest elements will be (n+1)/(r+1).

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