A rectangular container measuring 82 cm by 52 cm by 20 cm was to be filled with water by two taps, W and X. Tap W which fills the tank at a rate of 8 ℓ per minute was first turned on for 4 minutes before Tap X was turned on as well. If the tank was filled to the brim in a total of 5 minutes from the time when Tap W was first turned on, what is the rate at which Tap X fills the tank? Give your answer in ℓ per minute correct to 1 decimal place.
Total volume of the container
= 82 x 52 x 20
= 85280 cm
3 1 ℓ = 1000 cm
3 8 ℓ = 8000 cm
3 Volume of water filled by Tap W
= 8000 x 5
= 40000 cm
3 Volume of water filled by Tap X
= 85280 - 40000
= 45280 cm
3 Rate in which Tap X fills the container
= 45280 ÷ 1
= 45280 cm3/min
45280 mℓ/min
= 45.28 ℓ/min
≈ 45.3 ℓ/min (Correct to 1 decimal place)
Answer(s): 45.3 ℓ/min