A rectangular container measuring 76 cm by 60 cm by 35 cm was to be filled with water by two taps, M and N. Tap M which fills the tank at a rate of 9 ℓ per minute was first turned on for 2 minutes before Tap N was turned on as well. If the tank was filled to the brim in a total of 6 minutes from the time when Tap M was first turned on, what is the rate at which Tap N fills the tank? Give your answer in ℓ per minute correct to 1 decimal place.
Total volume of the container
= 76 x 60 x 35
= 159600 cm³ 

1 ℓ = 1000 cm³ 
9 ℓ = 9000 cm³ 

Volume of water filled by Tap M
= 9000 x 6
= 54000 cm³

Volume of water filled by Tap N
= 159600 - 54000
= 105600 cm³ 

Rate in which Tap N fills the container
= 105600 ÷ 4
26400 mℓ/min
= 26.4 ℓ/min
≈ 26.4 ℓ/min (Correct to 1 decimal place)

Answer(s): 26.4 ℓ/min