A rectangular container measuring 78 cm by 55 cm by 27 cm was to be filled with water by two taps, S and T. Tap S which fills the tank at a rate of 6 ℓ per minute was first turned on for 2 minutes before Tap T was turned on as well. If the tank was filled to the brim in a total of 7 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 container
= 78 x 55 x 27
= 115830 cm
3 1 ℓ = 1000 cm
3 6 ℓ = 6000 cm
3 Volume of water filled by Tap S
= 6000 x 7
= 42000 cm
3 Volume of water filled by Tap T
= 115830 - 42000
= 73830 cm
3 Rate in which Tap T fills the container
= 73830 ÷ 5
= 14766 cm3/min
14766 mℓ/min
= 14.766 ℓ/min
≈ 14.8 ℓ/min (Correct to 1 decimal place)
Answer(s): 14.8 ℓ/min