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From: aark@ihuxe.UUCP
Newsgroups: net.math,net.misc
Subject: A Different Simple Statistics Problem
Message-ID: <313@ihuxe.UUCP>
Date: Thu, 25-Aug-83 09:37:01 EDT
Article-I.D.: ihuxe.313
Posted: Thu Aug 25 09:37:01 1983
Date-Received: Thu, 25-Aug-83 21:26:16 EDT
Organization: BTL Naperville, Il.
Lines: 15


Now that we've beaten the three-cabinets-gold-and-silver-coins problem
to death, here's another simple problem in the same vein:

I have just written four letters to four different people and have
addressed the four envelopes.  In a fit of laziness I decide to stuff
the letters into the envelopes at random, rather than stuffing each
letter into the correct envelope.

What is the probability that exactly three of the letters get into the
right envelopes?
-- 
	Alan R. Kaminsky
	Bell Laboratories, Naperville, IL
	...ihnp4!ihuxe!aark