An empty rectangular container has a capacity of 158 ℓ and a height of 100 cm. At 10 a.m., Tap K is turned on to fill the container at a rate of 4 ℓ per minute for 18 minutes. After 10 minutes, Tap L is turned on to drain water from the container at a rate of 2 ℓ per minute for 11 minutes. What is the height of the water level in the container in the end? Give the answer in 1 decimal place.
1 ℓ = 1000 cm³ 
4 ℓ = 4000 cm³ 
2 ℓ = 2000 cm³ 
158 ℓ = 158000 cm³

Volume of water flowed in from Tap K
= 18 x 4000
= 72000 cm³

Volume of water from drained from Tap L
= 11 x 2000
= 22000 cm³

Volume of water left in the container
= 72000 - 22000
= 50000 cm³

Base area of the container
= 158000 ÷ 100
= 1580 cm² 

Height of water left in the container
= 50000 ÷ 1580
≈ 31.6 cm

Answer(s): 31.6 cm