The number of three digit numbers in which 9 appears only in one place is

The number of three digit numbers in which 9 appears only in one place is
  1. 243
  2. 234
  3. 217
  4. 225

Solution

The number of three digit numbers in which 9 appears at hun dred place only is = 1 × 9 × 9 = 81 Similarly, the number of three digit numbers in which 9 appears at ten or unit place only is = (8 × 1 × 9) × 2 = 144

Asked in: AP EAMCET 2018 (23 Apr Shift 2)

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