A rectangular tank measuring 79 cm by 55 cm by 20 cm was to be filled with water by two taps, F and G. Tap F which fills the tank at a rate of 8 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 5 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
= 79 x 55 x 20
= 86900 cm
3 1 ℓ = 1000 cm
3 8 ℓ = 8000 cm
3 Volume of water filled by Tap F
= 8000 x 5
= 40000 cm
3 Volume of water filled by Tap G
= 86900 - 40000
= 46900 cm
3 Rate in which Tap G fills the tank
= 46900 ÷ 2
= 23450 cm3/min
23450 mℓ/min
= 23.45 ℓ/min
≈ 23.5 ℓ/min (Correct to 1 decimal place)
Answer(s): 23.5 ℓ/min