A rectangular tank measuring 83 cm by 60 cm by 34 cm was to be filled with water by two taps, U and V. Tap U which fills the tank at a rate of 7 ℓ per minute was first turned on for 3 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
= 83 x 60 x 34
= 169320 cm
3 1 ℓ = 1000 cm
3 7 ℓ = 7000 cm
3 Volume of water filled by Tap U
= 7000 x 7
= 49000 cm
3 Volume of water filled by Tap V
= 169320 - 49000
= 120320 cm
3 Rate in which Tap V fills the tank
= 120320 ÷ 4
= 30080 cm3/min
30080 mℓ/min
= 30.08 ℓ/min
≈ 30.1 ℓ/min (Correct to 1 decimal place)
Answer(s): 30.1 ℓ/min