Fix the units digit: Since the number must be divisible by 5, the last digit has to be 5.

Choices for the first digit (hundreds place): The hundreds digit can be any odd number except 5, so the possible choices are 1, 3, 7, and 9.

Choices for the tens digit: The tens digit must also be an odd number and different from the hundreds and units digits. Since 5 is used in the units place, and we have already chosen one of the other four odd digits for the hundreds place, only 3 odd digits remain for the tens place.

Calculate total combinations: So, the total number of 3-digit numbers satisfying the conditions is: $4 \times 3 = 12$