perplexus.info :: Probability : Fair play

Fair play (Posted on 2011-12-30)

Two gamblers, A and B, divided into a few bundles the money they've recently won and agreed to toss a coin for each bundle.
A 3rd gambler, nicknamed Mathwiz remarked: "It is an even money that A will win at least five of the tosses".
How many bundles of money were there?

See The Solution Submitted by Ady TZIDON

Rating: 3.0000 (3 votes)

Comments: ( Back to comment list | You must be logged in to post comments.)

It doesn't take a Mathwiz (spoiler)

| Comment 1 of 3

If there are an odd number of tosses, then neither player can win exactly half of them. Therefore, half the time A wins more than half of them, and half the time B wins more than half of them.

If 5 is just over half of them, then n = 2 * (4.5) = 9

Edited on December 30, 2011, 6:26 pm

Posted by Steve Herman on 2011-12-30 11:24:28

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