How many 4-digit numbers are there having <strong>ALL</strong> digits as odd?
- A. 625 ✓
- B. 400
- C. 196
- D. 120
Correct Answer: A. 625
Explanation
The odd digits are 1, 3, 5, 7, 9. Since each of the 4 positions in the number can be filled in 5 ways, the total number of such 4-digit numbers is 5^4 = 625.
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