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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 's is

Options

  1. A64
  2. B72
  3. C81
  4. D900

Correct answer

C. 81

Step-by-step solution

If the last two digits is 0,0 , then in Ist digit any of the numbers except 0 i.e., 9 numbers If the last two digits is 1,1 , then in Ist digit any of the numbers except 0 and 1 , i.e. 8 numbers The total number of numbers =9+8 9=81

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