An empty rectangular container has a capacity of 105 ℓ and a height of 50 cm. At 9 a.m., Tap M is turned on to fill the container at a rate of 9 ℓ per minute for 17 minutes. After 13 minutes, Tap N is turned on to drain water from the container at a rate of 4 ℓ per minute for 11 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 
9 ℓ = 9000 cm³ 
4 ℓ = 4000 cm³ 
105 ℓ = 105000 cm³

Volume of water flowed in from Tap M
= 17 x 9000
= 153000 cm³

Volume of water from drained from Tap N
= 11 x 4000
= 44000 cm³

Volume of water left in the container
= 153000 - 44000
= 109000 cm³

Base area of the container
= 105000 ÷ 50
= 2100 cm² 

Height of water left in the container
= 109000 ÷ 2100
≈ 51.9 cm

Answer(s): 51.9 cm