An empty rectangular tank has a capacity of 192 ℓ and a height of 16 cm. At 8 a.m., Tap C is turned on to fill the tank at a rate of 9 ℓ per minute for 15 minutes. After 13 minutes, Tap D is turned on to drain water from the tank at a rate of 2 ℓ per minute for 13 minutes. What is the height of the water level in the tank in the end? Give the answer in 1 decimal place.
1 ℓ = 1000 cm³ 
9 ℓ = 9000 cm³ 
2 ℓ = 2000 cm³ 
192 ℓ = 192000 cm³

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

Volume of water from drained from Tap D
= 13 x 2000
= 26000 cm³

Volume of water left in the tank
= 135000 - 26000
= 109000 cm³

Base area of the tank
= 192000 ÷ 16
= 12000 cm² 

Height of water left in the tank
= 109000 ÷ 12000
≈ 9.1 cm

Answer(s): 9.1 cm