Explanation:

- Pipe A fills the tank in 24 hours, so its rate is 1/24 of the tank per hour.

- Efficiency ratio A:B = 5:3. Thus, B's rate = (3/5) × (1/24) = 1/40 per hour.

- Both pipes together fill (1/24 + 1/40) = (5+3)/120 = 8/120 = 1/15 of the tank per hour.

- But at the end of each hour, 1/4th of what was added is leaked. So only 3/4th remains each hour.

- Effective fill per hour = (3/4) × (1/15) = 1/20 of the tank.

- Time to fill = 20 hours.

The correct option is:

- Option:1, 20 Hr.