An empty rectangular tank has a capacity of 116 ℓ and a height of 25 cm. At 9 a.m., Tap V is turned on to fill the tank at a rate of 6 ℓ per minute for 18 minutes. After 8 minutes, Tap W is turned on to drain water from the tank at a rate of 5 ℓ per minute for 18 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 
6 ℓ = 6000 cm³ 
5 ℓ = 5000 cm³ 
116 ℓ = 116000 cm³

Volume of water flowed in from Tap V
= 18 x 6000
= 108000 cm³

Volume of water from drained from Tap W
= 18 x 5000
= 90000 cm³

Volume of water left in the tank
= 108000 - 90000
= 18000 cm³

Base area of the tank
= 116000 ÷ 25
= 4640 cm² 

Height of water left in the tank
= 18000 ÷ 4640
≈ 3.9 cm

Answer(s): 3.9 cm