A rectangular container measuring 76 cm by 57 cm by 26 cm was to be filled with water by two taps, J and K. Tap J which fills the tank at a rate of 9 ℓ per minute was first turned on for 3 minutes before Tap K was turned on as well. If the tank was filled to the brim in a total of 6 minutes from the time when Tap J was first turned on, what is the rate at which Tap K fills the tank? Give your answer in ℓ per minute correct to 1 decimal place.
Total volume of the container
= 76 x 57 x 26
= 112632 cm
3 1 ℓ = 1000 cm
3 9 ℓ = 9000 cm
3 Volume of water filled by Tap J
= 9000 x 6
= 54000 cm
3 Volume of water filled by Tap K
= 112632 - 54000
= 58632 cm
3 Rate in which Tap K fills the container
= 58632 ÷ 3
= 19544 cm3/min
19544 mℓ/min
= 19.544 ℓ/min
≈ 19.5 ℓ/min (Correct to 1 decimal place)
Answer(s): 19.5 ℓ/min