An empty rectangular tank has a capacity of 121 ℓ and a height of 125 cm. At 10 a.m., Tap S is turned on to fill the tank at a rate of 4 ℓ per minute for 17 minutes. After 12 minutes, Tap T is turned on to drain water from the tank at a rate of 2 ℓ per minute for 6 minutes. What is the height of the water level in the tank in the end? Give the answer in 1 decimal place.
1 ℓ = 1000 cm³ 
4 ℓ = 4000 cm³ 
2 ℓ = 2000 cm³ 
121 ℓ = 121000 cm³

Volume of water flowed in from Tap S
= 17 x 4000
= 68000 cm³

Volume of water from drained from Tap T
= 6 x 2000
= 12000 cm³

Volume of water left in the tank
= 68000 - 12000
= 56000 cm³

Base area of the tank
= 121000 ÷ 125
= 968 cm² 

Height of water left in the tank
= 56000 ÷ 968
≈ 57.9 cm

Answer(s): 57.9 cm