JEE MATHEMATICS MCQ: PERMUTATIONS

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A three digit number

n

is such that the last two digits of it are equal and differ from the first. The number of such

n'

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Correct option: C

Option C (81) is correct because there are 9 choices for the first digit (1-9) and 9 choices for the last two digits (00, 11, ..., 99) excluding the case where the first digit is equal to the last two.

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\left( {m + n} \right)

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