An empty rectangular container has a capacity of 120 ℓ and a height of 125 cm. At 6 a.m., Tap G is turned on to fill the container at a rate of 4 ℓ per minute for 20 minutes. After 8 minutes, Tap H is turned on to drain water from the container at a rate of 10 ℓ per minute for 5 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 
10 ℓ = 10000 cm³ 
120 ℓ = 120000 cm³

Volume of water flowed in from Tap G
= 20 x 4000
= 80000 cm³

Volume of water from drained from Tap H
= 5 x 10000
= 50000 cm³

Volume of water left in the container
= 80000 - 50000
= 30000 cm³

Base area of the container
= 120000 ÷ 125
= 960 cm² 

Height of water left in the container
= 30000 ÷ 960
≈ 31.3 cm

Answer(s): 31.3 cm