what is the answer to the below 'add detail'?
A large water tank in a country with a perfectly regular climate is exactly 48 feet high. During the rainy season, each day has exactly 12 hours of rainfall followed by 12 hours of evaporation. The water level in the tank increases at a uniform rate of 1 foot per hour during the 12 hours of rainfall, and it decreases at a uniform rate of half a foot per hour during the 12 hours of evaporation. If the tank is empty at the beginning of a 12 hour rainfall period, how many hours will it take for the water level in the tank to reach the top of the tank for the first time?
For example, after 12 hours the water level is 12 feet, while after 24 hours the level is 6 feet.