A rectangular tank measuring 86 cm by 60 cm by 39 cm was to be filled with water by two taps, T and U. Tap T which fills the tank at a rate of 5 ℓ per minute was first turned on for 3 minutes before Tap U was turned on as well. If the tank was filled to the brim in a total of 5 minutes from the time when Tap T was first turned on, what is the rate at which Tap U fills the tank? Give your answer in ℓ per minute correct to 1 decimal place.
Total volume of the tank
= 86 x 60 x 39
= 201240 cm
3 1 ℓ = 1000 cm
3 5 ℓ = 5000 cm
3 Volume of water filled by Tap T
= 5000 x 5
= 25000 cm
3 Volume of water filled by Tap U
= 201240 - 25000
= 176240 cm
3 Rate in which Tap U fills the tank
= 176240 ÷ 2
= 88120 cm3/min
88120 mℓ/min
= 88.12 ℓ/min
≈ 88.1 ℓ/min (Correct to 1 decimal place)
Answer(s): 88.1 ℓ/min