Q182 / 270 · NDA 2018 (Phase 2) · Mathematics
The total number of 5-digit numbers that can be composed of distinct digits from 0 to 9 is
- A45360
- B30240
- Correct answerC27216
- D15120
Solution
Number of 5 digits numbers with all distinct digit is same as filling of 5 vacent placed out of 10 boxes.
First digit of any number can be choosen in 9 ways.
Remaining 4 digits can be choosen in remaining 9 digits in ${ }^9 \mathrm{P}_4$ ways.
Total number of such number
$=9 \times 9 \times 8 \times 7 \times 6=27216$
Hence, the correct answer is option: 'C'.