Do some research onderangements.

What does D(5) equal?

The answer to your problem is

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- October 22nd 2007, 04:03 PM #1

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- Oct 2007
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## Help pls.

The Heavenrich family of five people randomly picks a name of a family member from a hat to decide for whom to buy a present.

**What is the probability that nobody picks their own name?**If someone picks their own name, all the names are returned and everyone picks again.**What is the probability that it took exactly two tries for everyone to pick a name of another family member"**

- October 22nd 2007, 04:15 PM #2

- October 25th 2007, 05:18 PM #3

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