A rectangular container measuring 88 cm by 51 cm by 20 cm was to be filled with water by two taps, Z and A. Tap Z which fills the tank at a rate of 9 ℓ per minute was first turned on for 2 minutes before Tap A was turned on as well. If the tank was filled to the brim in a total of 6 minutes from the time when Tap Z was first turned on, what is the rate at which Tap A fills the tank? Give your answer in ℓ per minute correct to 1 decimal place.
Total volume of the container
= 88 x 51 x 20
= 89760 cm
3 1 ℓ = 1000 cm
3 9 ℓ = 9000 cm
3 Volume of water filled by Tap Z
= 9000 x 6
= 54000 cm
3 Volume of water filled by Tap A
= 89760 - 54000
= 35760 cm
3 Rate in which Tap A fills the container
= 35760 ÷ 4
= 8940 cm3/min
8940 mℓ/min
= 8.94 ℓ/min
≈ 8.9 ℓ/min (Correct to 1 decimal place)
Answer(s): 8.9 ℓ/min