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#1 2007-04-02 10:10:20
- Prakash Panneer
- Member
- Registered: 2006-06-01
- Posts: 110
Algebra
John Doe works for a packaging company. One day, he received five different orders and accidentally mixed up the addresses. So he applied address labels randomly on the packages.What is the probability that exactly four packages were correctly labeled?
Thanks in Advance 
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#2 2007-04-02 10:16:19
- JaneFairfax
- Member
- Registered: 2007-02-23
- Posts: 6,868
Re: Algebra
If four packages are correctly labelled, the last label must correctly match the last package. In other words, we want to find the probability that all five packages are correctly labelled, and thats 1⁄5! = 1⁄120. 
EDIT: Or do you really mean EXACTLY four packages correctly labelled? That wouldnt be possible because, as I said, the last label must be the correct one for the last package if the other four were correctly marked. 
Last edited by JaneFairfax (2007-04-02 10:20:48)
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