An empty rectangular tank has a capacity of 112 ℓ and a height of 35 cm. At 10 a.m., Tap Y is turned on to fill the tank at a rate of 3 ℓ per minute for 19 minutes. After 6 minutes, Tap Z is turned on to drain water from the tank at a rate of 3 ℓ per minute for 11 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 
3 ℓ = 3000 cm³ 
3 ℓ = 3000 cm³ 
112 ℓ = 112000 cm³

Volume of water flowed in from Tap Y
= 19 x 3000
= 57000 cm³

Volume of water from drained from Tap Z
= 11 x 3000
= 33000 cm³

Volume of water left in the tank
= 57000 - 33000
= 24000 cm³

Base area of the tank
= 112000 ÷ 35
= 3200 cm² 

Height of water left in the tank
= 24000 ÷ 3200
≈ 7.5 cm

Answer(s): 7.5 cm