A rectangular tank measuring 90 cm by 57 cm by 39 cm was to be filled with water by two taps, S and T. Tap S which fills the tank at a rate of 9 ℓ per minute was first turned on for 4 minutes before Tap T was turned on as well. If the tank was filled to the brim in a total of 5 minutes from the time when Tap S was first turned on, what is the rate at which Tap T fills the tank? Give your answer in ℓ per minute correct to 1 decimal place.
Total volume of the tank
= 90 x 57 x 39
= 200070 cm
3 1 ℓ = 1000 cm
3 9 ℓ = 9000 cm
3 Volume of water filled by Tap S
= 9000 x 5
= 45000 cm
3 Volume of water filled by Tap T
= 200070 - 45000
= 155070 cm
3 Rate in which Tap T fills the tank
= 155070 ÷ 1
= 155070 cm3/min
155070 mℓ/min
= 155.07 ℓ/min
≈ 155.1 ℓ/min (Correct to 1 decimal place)
Answer(s): 155.1 ℓ/min