A rectangular tank measuring 71 cm by 57 cm by 38 cm was to be filled with water by two taps, Y and Z. Tap Y which fills the tank at a rate of 5 ℓ per minute was first turned on for 3 minutes before Tap Z was turned on as well. If the tank was filled to the brim in a total of 6 minutes from the time when Tap Y was first turned on, what is the rate at which Tap Z fills the tank? Give your answer in ℓ per minute correct to 1 decimal place.
Total volume of the tank
= 71 x 57 x 38
= 153786 cm
3 1 ℓ = 1000 cm
3 5 ℓ = 5000 cm
3 Volume of water filled by Tap Y
= 5000 x 6
= 30000 cm
3 Volume of water filled by Tap Z
= 153786 - 30000
= 123786 cm
3 Rate in which Tap Z fills the tank
= 123786 ÷ 3
= 41262 cm3/min
41262 mℓ/min
= 41.262 ℓ/min
≈ 41.3 ℓ/min (Correct to 1 decimal place)
Answer(s): 41.3 ℓ/min