Explanation:

- Pipe A can fill the tank in 24 hours. Therefore, Pipe A fills 1/24 of the tank per hour.

- The efficiency of pipes A and B is in the ratio of 5:3. Hence, Pipe B fills (3/5) of what Pipe A fills per hour.

- Pipe B fills (3/5) * (1/24) = 1/40 of the tank per hour.

- Together, A and B fill (1/24 + 1/40) = 1/15 of the tank per hour.

- Due to leakage, one-fourth of the water added each hour by both pipes is lost.

- Effective filling per hour = (1/15) - (1/4) * (1/15) = (3/60) = 1/20 of the tank.

- Thus, the time required to fill the tank completely is 20 hours.

So, the correct option is:

- Option 1: 20 Hr.