AP EAMCET · Maths · Permutation Combination
The number of three digit numbers in which 9 appears only in one place is
- A 243
- B 234
- C 217
- D 225
Answer & Solution
Correct Answer
(D) 225
Step-by-step Solution
Detailed explanation
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
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