Five Balls of different colour
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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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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.
For a discussion of this concept, check my posts here:
https://www.beatthegmat.com/permutation- ... 21513.html
A derangement is an arrangement in which NO ELEMENT is in the correct position.
For a discussion of this concept, check my posts here:
https://www.beatthegmat.com/permutation- ... 21513.html
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Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.
As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.
For more information, please email me (Mitch Hunt) at [email protected].
Student Review #1
Student Review #2
Student Review #3