An empty rectangular container has a capacity of 156 ℓ and a height of 48 cm. At 6 a.m., Tap E is turned on to fill the container at a rate of 6 ℓ per minute for 20 minutes. After 8 minutes, Tap F is turned on to drain water from the container at a rate of 7 ℓ per minute for 7 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 
7 ℓ = 7000 cm³ 
156 ℓ = 156000 cm³

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

Volume of water from drained from Tap F
= 7 x 7000
= 49000 cm³

Volume of water left in the container
= 120000 - 49000
= 71000 cm³

Base area of the container
= 156000 ÷ 48
= 3250 cm² 

Height of water left in the container
= 71000 ÷ 3250
≈ 21.8 cm

Answer(s): 21.8 cm