A rectangular container measuring 87 cm by 55 cm by 29 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 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
= 87 x 55 x 29
= 138765 cm
3 1 ℓ = 1000 cm
3 9 ℓ = 9000 cm
3 Volume of water filled by Tap S
= 9000 x 7
= 63000 cm
3 Volume of water filled by Tap T
= 138765 - 63000
= 75765 cm
3 Rate in which Tap T fills the container
= 75765 ÷ 3
= 25255 cm3/min
25255 mℓ/min
= 25.255 ℓ/min
≈ 25.3 ℓ/min (Correct to 1 decimal place)
Answer(s): 25.3 ℓ/min