An empty rectangular container has a capacity of 144 ℓ and a height of 36 cm. At 6 a.m., Tap M is turned on to fill the container at a rate of 8 ℓ per minute for 20 minutes. After 9 minutes, Tap N is turned on to drain water from the container at a rate of 2 ℓ per minute for 27 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 
2 ℓ = 2000 cm³ 
144 ℓ = 144000 cm³

Volume of water flowed in from Tap M
= 20 x 8000
= 160000 cm³

Volume of water from drained from Tap N
= 27 x 2000
= 54000 cm³

Volume of water left in the container
= 160000 - 54000
= 106000 cm³

Base area of the container
= 144000 ÷ 36
= 4000 cm² 

Height of water left in the container
= 106000 ÷ 4000
≈ 26.5 cm

Answer(s): 26.5 cm