A rectangular container measuring 90 cm by 53 cm by 38 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 3 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
= 90 x 53 x 38
= 181260 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
= 181260 - 54000
= 127260 cm
3 Rate in which Tap A fills the container
= 127260 ÷ 3
= 42420 cm3/min
42420 mℓ/min
= 42.42 ℓ/min
≈ 42.4 ℓ/min (Correct to 1 decimal place)
Answer(s): 42.4 ℓ/min