An empty rectangular container has a capacity of 168 ℓ and a height of 200 cm. At 6 a.m., Tap Z is turned on to fill the container at a rate of 4 ℓ per minute for 20 minutes. After 4 minutes, Tap A is turned on to drain water from the container at a rate of 4 ℓ per minute for 7 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 
4 ℓ = 4000 cm³ 
168 ℓ = 168000 cm³

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

Volume of water from drained from Tap A
= 7 x 4000
= 28000 cm³

Volume of water left in the container
= 80000 - 28000
= 52000 cm³

Base area of the container
= 168000 ÷ 200
= 840 cm² 

Height of water left in the container
= 52000 ÷ 840
≈ 61.9 cm

Answer(s): 61.9 cm