Question

The number of all 8-digit odd numbers is:

• A. \( 45 \times 10^6 \)
• B. \( 90 \times 10^6 \)
• C. \( 9 \times 10^8 \)
• D. \( 9 \times 10^6 \)

Hint:

For counting numbers with specific conditions, multiply the possible choices for each digit place.

Answer 1

The Correct Option is A

To find the number of 8-digit odd numbers, consider the following: - The first digit must be any digit from 1 to 9 (9 options). - The last digit must be an odd number, i.e., 1, 3, 5, 7, or 9 (5 options). - The remaining 6 digits can be any digit from 0 to 9 (10 options each). Thus, the total number of 8-digit odd numbers is: \[ 9 \times 10^6 \times 5 = 45 \times 10^6 \]