(i) Digits are not repeated:

The first digit must be 3 or 4 to ensure the number is between 3000 and 5000. This gives us 2 choices for the first digit.

After choosing the first digit, we have 4 remaining digits. We need to choose 3 more digits from these 4, which can be done in:

\(4 \times 3 \times 2 = 24\)

Thus, the total number of ways is:

\(2 \times 24 = 48\)

(ii) Digits can be repeated and the number is odd:

The last digit must be odd, so it can be 1, 3, or 5. This gives us 3 choices for the last digit.

The first digit must be 3 or 4 to ensure the number is between 3000 and 5000. This gives us 2 choices for the first digit.

The middle two digits can be any of the 5 digits (1, 2, 3, 4, 5) and can be repeated. Therefore, there are:

\(5 \times 5 = 25\)

ways to choose the middle two digits.

Thus, the total number of ways is:

\(2 \times 25 \times 3 = 150\)