An empty rectangular container has a capacity of 60 ℓ and a height of 15 cm. At 8 a.m., Tap K is turned on to fill the container at a rate of 6 ℓ per minute for 20 minutes. After 15 minutes, Tap L is turned on to drain water from the container at a rate of 2 ℓ per minute for 13 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 
6 ℓ = 6000 cm³ 
2 ℓ = 2000 cm³ 
60 ℓ = 60000 cm³

Volume of water flowed in from Tap K
= 20 x 6000
= 120000 cm³

Volume of water from drained from Tap L
= 13 x 2000
= 26000 cm³

Volume of water left in the container
= 120000 - 26000
= 94000 cm³

Base area of the container
= 60000 ÷ 15
= 4000 cm² 

Height of water left in the container
= 94000 ÷ 4000
≈ 23.5 cm

Answer(s): 23.5 cm