alleryHow many 5-digit numbers can be formed using digits 1-9 (no repetition)?
A5!
B9P5 = 9!/4! = 15120
C9 × 5
D9⁵
Answer & Solution
Correct answer: B. 9P5 = 9!/4! = 15120
9 choices for 1st digit, 8 for 2nd, ..., 5 for 5th.
9P5 = 9 × 8 × 7 × 6 × 5 = 15120.
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