An empty rectangular container has a capacity of 119 ℓ and a height of 34 cm. At 8 a.m., Tap D is turned on to fill the container at a rate of 8 ℓ per minute for 18 minutes. After 11 minutes, Tap E is turned on to drain water from the container at a rate of 5 ℓ per minute for 21 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 
8 ℓ = 8000 cm³ 
5 ℓ = 5000 cm³ 
119 ℓ = 119000 cm³

Volume of water flowed in from Tap D
= 18 x 8000
= 144000 cm³

Volume of water from drained from Tap E
= 21 x 5000
= 105000 cm³

Volume of water left in the container
= 144000 - 105000
= 39000 cm³

Base area of the container
= 119000 ÷ 34
= 3500 cm² 

Height of water left in the container
= 39000 ÷ 3500
≈ 11.1 cm

Answer(s): 11.1 cm