An empty rectangular container has a capacity of 26 ℓ and a height of 20 cm. At 10 a.m., Tap Q is turned on to fill the container at a rate of 7 ℓ per minute for 17 minutes. After 4 minutes, Tap R is turned on to drain water from the container at a rate of 3 ℓ per minute for 25 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 
7 ℓ = 7000 cm³ 
3 ℓ = 3000 cm³ 
26 ℓ = 26000 cm³

Volume of water flowed in from Tap Q
= 17 x 7000
= 119000 cm³

Volume of water from drained from Tap R
= 25 x 3000
= 75000 cm³

Volume of water left in the container
= 119000 - 75000
= 44000 cm³

Base area of the container
= 26000 ÷ 20
= 1300 cm² 

Height of water left in the container
= 44000 ÷ 1300
≈ 33.8 cm

Answer(s): 33.8 cm