Question
A rectangular tank measuring 84 cm by 56 cm by 38 cm was to be filled with water by two taps, D and E. Tap D which fills the tank at a rate of 9 ℓ per minute was first turned on for 4 minutes before Tap E was turned on as well. If the tank was filled to the brim in a total of 5 minutes from the time when Tap D was first turned on, what is the rate at which Tap E fills the tank? Give your answer in ℓ per minute correct to 1 decimal place.
3 m

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A rectangular tank measuring 84 cm by 56 cm by 38 cm was to be filled with water by two taps, D and E. Tap D which fills the tank at a rate of 9 ℓ per minute was first turned on for 4 minutes before Tap E was turned on as well. If the tank was filled to the brim in a total of 5 minutes from the time when Tap D was first turned on, what is the rate at which Tap E fills the tank? Give your answer in ℓ per minute correct to 1 decimal place.