A rectangular tank measuring 85 cm by 60 cm by 20 cm was to be filled with water by two taps, E and F. Tap E which fills the tank at a rate of 7 ℓ per minute was first turned on for 2 minutes before Tap F was turned on as well. If the tank was filled to the brim in a total of 7 minutes from the time when Tap E was first turned on, what is the rate at which Tap F fills the tank? Give your answer in ℓ per minute correct to 1 decimal place.
Total volume of the tank
= 85 x 60 x 20
= 102000 cm
3 1 ℓ = 1000 cm
3 7 ℓ = 7000 cm
3 Volume of water filled by Tap E
= 7000 x 7
= 49000 cm
3 Volume of water filled by Tap F
= 102000 - 49000
= 53000 cm
3 Rate in which Tap F fills the tank
= 53000 ÷ 5
= 10600 cm3/min
10600 mℓ/min
= 10.6 ℓ/min
≈ 10.6 ℓ/min (Correct to 1 decimal place)
Answer(s): 10.6 ℓ/min