A rectangular container measuring 79 cm by 51 cm by 24 cm was to be filled with water by two taps, N and P. Tap N which fills the tank at a rate of 7 ℓ per minute was first turned on for 3 minutes before Tap P was turned on as well. If the tank was filled to the brim in a total of 5 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
= 79 x 51 x 24
= 96696 cm
3 1 ℓ = 1000 cm
3 7 ℓ = 7000 cm
3 Volume of water filled by Tap N
= 7000 x 5
= 35000 cm
3 Volume of water filled by Tap P
= 96696 - 35000
= 61696 cm
3 Rate in which Tap P fills the container
= 61696 ÷ 2
= 30848 cm3/min
30848 mℓ/min
= 30.848 ℓ/min
≈ 30.8 ℓ/min (Correct to 1 decimal place)
Answer(s): 30.8 ℓ/min