An empty rectangular tank has a capacity of 174 ℓ and a height of 125 cm. At 9 a.m., Tap A is turned on to fill the tank at a rate of 7 ℓ per minute for 17 minutes. After 10 minutes, Tap B is turned on to drain water from the tank at a rate of 7 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 
7 ℓ = 7000 cm³ 
7 ℓ = 7000 cm³ 
174 ℓ = 174000 cm³

Volume of water flowed in from Tap A
= 17 x 7000
= 119000 cm³

Volume of water from drained from Tap B
= 6 x 7000
= 42000 cm³

Volume of water left in the tank
= 119000 - 42000
= 77000 cm³

Base area of the tank
= 174000 ÷ 125
= 1392 cm² 

Height of water left in the tank
= 77000 ÷ 1392
≈ 55.3 cm

Answer(s): 55.3 cm