An empty rectangular container has a capacity of 129 ℓ and a height of 25 cm. At 8 a.m., Tap V is turned on to fill the container at a rate of 10 ℓ per minute for 17 minutes. After 4 minutes, Tap W is turned on to drain water from the container at a rate of 5 ℓ per minute for 13 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 
10 ℓ = 10000 cm³ 
5 ℓ = 5000 cm³ 
129 ℓ = 129000 cm³

Volume of water flowed in from Tap V
= 17 x 10000
= 170000 cm³

Volume of water from drained from Tap W
= 13 x 5000
= 65000 cm³

Volume of water left in the container
= 170000 - 65000
= 105000 cm³

Base area of the container
= 129000 ÷ 25
= 5160 cm² 

Height of water left in the container
= 105000 ÷ 5160
≈ 20.3 cm

Answer(s): 20.3 cm