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InterviewSolution
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The number of arrangments of all digits of `12345` such that at least `3` digits will not come in its position is |
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Answer» Correct Answer - 109 Total number of ways such that at least 3 digits will not come in its position. =Derangement of 3 digits +Derangement of 4 digits +Derangement of 5 digits `= ""^(5)C_(3)xx3!xx(1-(1)/(1!)+(1)/(2!)-(1)/(3!))+""^(5)C_(4)xx4!xx(1-(1)/(1!)+(1)/(2!)-(1)/(3!)+(1)/(4!))+""^(5)C_(5)xx5!xx(1-(1)/(1!)+(1)/(2!)-(1)/(3!)+(1)/(4!)-(1)/(5!))` `=10xx2+5xx9+44` `=20+45+44=109` |
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