A rectangular tank measuring 85 cm by 52 cm by 24 cm was to be filled with water by two taps, F and G. Tap F which fills the tank at a rate of 6 ℓ per minute was first turned on for 3 minutes before Tap G was turned on as well. If the tank was filled to the brim in a total of 6 minutes from the time when Tap F was first turned on, what is the rate at which Tap G fills the tank? Give your answer in ℓ per minute correct to 1 decimal place.
Total volume of the tank
= 85 x 52 x 24
= 106080 cm³ 

1 ℓ = 1000 cm³ 
6 ℓ = 6000 cm³ 

Volume of water filled by Tap F
= 6000 x 6
= 36000 cm³

Volume of water filled by Tap G
= 106080 - 36000
= 70080 cm³ 

Rate in which Tap G fills the tank
= 70080 ÷ 3
23360 mℓ/min
= 23.36 ℓ/min
≈ 23.4 ℓ/min (Correct to 1 decimal place)

Answer(s): 23.4 ℓ/min