A rectangular container measuring 80 cm by 56 cm by 27 cm was to be filled with water by two taps, B and C. Tap B which fills the tank at a rate of 7 ℓ per minute was first turned on for 3 minutes before Tap C was turned on as well. If the tank was filled to the brim in a total of 6 minutes from the time when Tap B was first turned on, what is the rate at which Tap C fills the tank? Give your answer in ℓ per minute correct to 1 decimal place.
Total volume of the container
= 80 x 56 x 27
= 120960 cm
3 1 ℓ = 1000 cm
3 7 ℓ = 7000 cm
3 Volume of water filled by Tap B
= 7000 x 6
= 42000 cm
3 Volume of water filled by Tap C
= 120960 - 42000
= 78960 cm
3 Rate in which Tap C fills the container
= 78960 ÷ 3
= 26320 cm3/min
26320 mℓ/min
= 26.32 ℓ/min
≈ 26.3 ℓ/min (Correct to 1 decimal place)
Answer(s): 26.3 ℓ/min