An empty rectangular container has a capacity of 117 ℓ and a height of 25 cm. At 7 a.m., Tap A is turned on to fill the container at a rate of 9 ℓ per minute for 15 minutes. After 11 minutes, Tap B is turned on to drain water from the container at a rate of 5 ℓ per minute for 25 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 
9 ℓ = 9000 cm³ 
5 ℓ = 5000 cm³ 
117 ℓ = 117000 cm³

Volume of water flowed in from Tap A
= 15 x 9000
= 135000 cm³

Volume of water from drained from Tap B
= 25 x 5000
= 125000 cm³

Volume of water left in the container
= 135000 - 125000
= 10000 cm³

Base area of the container
= 117000 ÷ 25
= 4680 cm² 

Height of water left in the container
= 10000 ÷ 4680
≈ 2.1 cm

Answer(s): 2.1 cm