An empty rectangular container has a capacity of 200 ℓ and a height of 10 cm. At 7 a.m., Tap R is turned on to fill the container at a rate of 7 ℓ per minute for 18 minutes. After 12 minutes, Tap S 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 
7 ℓ = 7000 cm³ 
6 ℓ = 6000 cm³ 
200 ℓ = 200000 cm³

Volume of water flowed in from Tap R
= 18 x 7000
= 126000 cm³

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

Volume of water left in the container
= 126000 - 72000
= 54000 cm³

Base area of the container
= 200000 ÷ 10
= 20000 cm² 

Height of water left in the container
= 54000 ÷ 20000
≈ 2.7 cm

Answer(s): 2.7 cm