A rectangular container measuring 79 cm by 51 cm by 32 cm was to be filled with water by two taps, S and T. Tap S which fills the tank at a rate of 7 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 6 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
= 79 x 51 x 32
= 128928 cm
3 1 ℓ = 1000 cm
3 7 ℓ = 7000 cm
3 Volume of water filled by Tap S
= 7000 x 6
= 42000 cm
3 Volume of water filled by Tap T
= 128928 - 42000
= 86928 cm
3 Rate in which Tap T fills the container
= 86928 ÷ 2
= 43464 cm3/min
43464 mℓ/min
= 43.464 ℓ/min
≈ 43.5 ℓ/min (Correct to 1 decimal place)
Answer(s): 43.5 ℓ/min