Question 28
Back to Exercise
How many 3-digit numbers have all three digits different?
- A 720
- B 504
- C 648 Correct
- D 900
Correct Answer: Option C
First digit 1–9: 9 ways
Second: 9 (0 now allowed); third: 8
9 × 9 × 8 = 648
Trap: 720 lets 0 lead.
Answer: 648
Discussion & Comments 0
Share your method, a shortcut, or ask about a step you didn't follow.
No comments yet. Be the first to share your solution!