A rectangular tank measuring 74 cm by 53 cm by 22 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 4 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 tank
= 74 x 53 x 22
= 86284 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
= 86284 - 54000
= 32284 cm
3 Rate in which Tap K fills the tank
= 32284 ÷ 2
= 16142 cm3/min
16142 mℓ/min
= 16.142 ℓ/min
≈ 16.1 ℓ/min (Correct to 1 decimal place)
Answer(s): 16.1 ℓ/min