Question

The total number of four-digit odd numbers that can be formed using 0, 1, 2, 3, 5, and 7 (repetition allowed) is

• A. 216
• B. 375
• C. 400
• D. 720

Answer 1

The correct option is D 720

Thousands place can be filled with any of the digits 1, 2, 3, 5, 7 i.e., in 5 ways.
Hundredth and tenth place can be filled with any of the digits in 6 ways.
Unit place can be filled with any of the digits 1, 3, 5, 7 i.e., in 4 ways.
$\therefore$ Total number of numbers = $5\times 6\times 6\times 4=720$