An empty rectangular container has a capacity of 89 ℓ and a height of 200 cm. At 8 a.m., Tap P is turned on to fill the container at a rate of 5 ℓ per minute for 15 minutes. After 2 minutes, Tap Q is turned on to drain water from the container at a rate of 6 ℓ per minute for 12 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 
5 ℓ = 5000 cm³ 
6 ℓ = 6000 cm³ 
89 ℓ = 89000 cm³

Volume of water flowed in from Tap P
= 15 x 5000
= 75000 cm³

Volume of water from drained from Tap Q
= 12 x 6000
= 72000 cm³

Volume of water left in the container
= 75000 - 72000
= 3000 cm³

Base area of the container
= 89000 ÷ 200
= 445 cm² 

Height of water left in the container
= 3000 ÷ 445
≈ 6.7 cm

Answer(s): 6.7 cm