A rectangular tank measuring 70 cm by 53 cm by 37 cm was to be filled with water by two taps, U and V. Tap U which fills the tank at a rate of 5 ℓ per minute was first turned on for 4 minutes before Tap V was turned on as well. If the tank was filled to the brim in a total of 7 minutes from the time when Tap U was first turned on, what is the rate at which Tap V fills the tank? Give your answer in ℓ per minute correct to 1 decimal place.
Total volume of the tank
= 70 x 53 x 37
= 137270 cm
3 1 ℓ = 1000 cm
3 5 ℓ = 5000 cm
3 Volume of water filled by Tap U
= 5000 x 7
= 35000 cm
3 Volume of water filled by Tap V
= 137270 - 35000
= 102270 cm
3 Rate in which Tap V fills the tank
= 102270 ÷ 3
= 34090 cm3/min
34090 mℓ/min
= 34.09 ℓ/min
≈ 34.1 ℓ/min (Correct to 1 decimal place)
Answer(s): 34.1 ℓ/min