Question

Write the smallest $8$-digit odd number using all odd digits.

Answer 1

Forming the smallest $8$-digit odd number using all odd digits:

1. While forming a smallest number using given digits, arrange the digits in ascending order from left.
2. To form a smallest number by repeating its digits, repeat the smallest digit.

Odd digits are $1,3,5,7,9$.

Thus, the smallest $8$-digit odd number using all odd digits is $1,11,13,579$.