Level 3
A rectangular tank measuring 60 cm by 50 cm by 25 cm was to be filled with water by two taps, A and B. Tap A which fills the tank at a rate of 8ℓ per minute was first turned on for 5 minutes before Tap B was turned on as well. If the tank was filled to the brim in a total of 7 minutes from the time when Tap A was first turned on, what is the rate at which Tap B fills the tank? Give the answer in ℓ per minute correct to 1 decimal place.

Level 3
An empty rectangular tank has a capacity of 90ℓ and a height of 50 cm. At 10 am, Tap A is turned on to fill the tank at a rate of 4ℓ per minute for 15 minutes. After 5 minutes, Tap B is turned on to drain water from the tank at a rate of 2ℓ per minute for 18 minutes. What is the height of the water level in the tank in the end? Express the answer in 1 decimal place.

Level 3
A tank with a square base area of 121 cm² is 60% filled with water. If 4 pails of water are poured into the tank, 756 cm³ of water would overflow. If 3 pails of water are poured into the tank, 128 cm³ of water would overflow. What is the height of the tank ? Give the answer to one decimal place.