An empty rectangular tank has a capacity of 117 ℓ and a height of 65 cm. At 8 a.m., Tap F is turned on to fill the tank at a rate of 5 ℓ per minute for 19 minutes. After 15 minutes, Tap G is turned on to drain water from the tank at a rate of 8 ℓ per minute for 5 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 
5 ℓ = 5000 cm³ 
8 ℓ = 8000 cm³ 
117 ℓ = 117000 cm³

Volume of water flowed in from Tap F
= 19 x 5000
= 95000 cm³

Volume of water from drained from Tap G
= 5 x 8000
= 40000 cm³

Volume of water left in the tank
= 95000 - 40000
= 55000 cm³

Base area of the tank
= 117000 ÷ 65
= 1800 cm² 

Height of water left in the tank
= 55000 ÷ 1800
≈ 30.6 cm

Answer(s): 30.6 cm