An empty rectangular container has a capacity of 78 ℓ and a height of 65 cm. At 10 a.m., Tap P is turned on to fill the container at a rate of 3 ℓ per minute for 19 minutes. After 7 minutes, Tap Q is turned on to drain water from the container at a rate of 2 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 
3 ℓ = 3000 cm³ 
2 ℓ = 2000 cm³ 
78 ℓ = 78000 cm³

Volume of water flowed in from Tap P
= 19 x 3000
= 57000 cm³

Volume of water from drained from Tap Q
= 11 x 2000
= 22000 cm³

Volume of water left in the container
= 57000 - 22000
= 35000 cm³

Base area of the container
= 78000 ÷ 65
= 1200 cm² 

Height of water left in the container
= 35000 ÷ 1200
≈ 29.2 cm

Answer(s): 29.2 cm