A rectangular container measuring 72 cm by 51 cm by 30 cm was to be filled with water by two taps, J and K. Tap J which fills the tank at a rate of 8 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 5 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
= 72 x 51 x 30
= 110160 cm
3 1 ℓ = 1000 cm
3 8 ℓ = 8000 cm
3 Volume of water filled by Tap J
= 8000 x 5
= 40000 cm
3 Volume of water filled by Tap K
= 110160 - 40000
= 70160 cm
3 Rate in which Tap K fills the container
= 70160 ÷ 2
= 35080 cm3/min
35080 mℓ/min
= 35.08 ℓ/min
≈ 35.1 ℓ/min (Correct to 1 decimal place)
Answer(s): 35.1 ℓ/min