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Five Balls of different colour

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Five Balls of different colour

by hjafferi » Mon Jun 24, 2013 9:55 am
There are 5 balls of different colours and 5 boxes of colours the same as those of the balls. Number of ways in which the balls, one in each box can be placed such that a ball does not go to a box of its own colour is
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by GMATGuruNY » Mon Jun 24, 2013 11:00 am
I believe that the question stem is asking for the number of DERANGEMENTS.
A derangement is an arrangement in which NO ELEMENT is in the correct position.
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