Hello, sharkman!

We have a four-digit number.How many 4-digit odd numbers greater than 3,000 can be formed

by using the digits 0-9 if digits may be repeated?

The first (leftmost) digit can be any of {3, 4, 5, 6, 7, 8, 9} . . . 7 choices.

The second digit can be any of the 10 digits.

The third digit can be any of the 10 digits.

The last (rightmost) digit can be any of {1, 3, 5, 7, 9} . . . 5 choices.

Therefore . . .