A rectangular tank measuring 85 cm by 58 cm by 26 cm was to be filled with water by two taps, H and J. Tap H which fills the tank at a rate of 7 ℓ per minute was first turned on for 4 minutes before Tap J was turned on as well. If the tank was filled to the brim in a total of 6 minutes from the time when Tap H was first turned on, what is the rate at which Tap J fills the tank? Give your answer in ℓ per minute correct to 1 decimal place.
Total volume of the tank
= 85 x 58 x 26
= 128180 cm
3 1 ℓ = 1000 cm
3 7 ℓ = 7000 cm
3 Volume of water filled by Tap H
= 7000 x 6
= 42000 cm
3 Volume of water filled by Tap J
= 128180 - 42000
= 86180 cm
3 Rate in which Tap J fills the tank
= 86180 ÷ 2
= 43090 cm3/min
43090 mℓ/min
= 43.09 ℓ/min
≈ 43.1 ℓ/min (Correct to 1 decimal place)
Answer(s): 43.1 ℓ/min