An empty rectangular container has a capacity of 195 ℓ and a height of 20 cm. At 10 a.m., Tap E is turned on to fill the container at a rate of 6 ℓ per minute for 17 minutes. After 4 minutes, Tap F is turned on to drain water from the container at a rate of 4 ℓ per minute for 12 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 
4 ℓ = 4000 cm³ 
195 ℓ = 195000 cm³

Volume of water flowed in from Tap E
= 17 x 6000
= 102000 cm³

Volume of water from drained from Tap F
= 12 x 4000
= 48000 cm³

Volume of water left in the container
= 102000 - 48000
= 54000 cm³

Base area of the container
= 195000 ÷ 20
= 9750 cm² 

Height of water left in the container
= 54000 ÷ 9750
≈ 5.5 cm

Answer(s): 5.5 cm