A rectangular container measuring 84 cm by 58 cm by 35 cm was to be filled with water by two taps, N and P. Tap N which fills the tank at a rate of 9 ℓ per minute was first turned on for 4 minutes before Tap P was turned on as well. If the tank was filled to the brim in a total of 6 minutes from the time when Tap N was first turned on, what is the rate at which Tap P fills the tank? Give your answer in ℓ per minute correct to 1 decimal place.
Total volume of the container
= 84 x 58 x 35
= 170520 cm
3 1 ℓ = 1000 cm
3 9 ℓ = 9000 cm
3 Volume of water filled by Tap N
= 9000 x 6
= 54000 cm
3 Volume of water filled by Tap P
= 170520 - 54000
= 116520 cm
3 Rate in which Tap P fills the container
= 116520 ÷ 2
= 58260 cm3/min
58260 mℓ/min
= 58.26 ℓ/min
≈ 58.3 ℓ/min (Correct to 1 decimal place)
Answer(s): 58.3 ℓ/min