A rectangular container measuring 82 cm by 52 cm by 35 cm was to be filled with water by two taps, U and V. Tap U which fills the tank at a rate of 8 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 container
= 82 x 52 x 35
= 149240 cm
3 1 ℓ = 1000 cm
3 8 ℓ = 8000 cm
3 Volume of water filled by Tap U
= 8000 x 7
= 56000 cm
3 Volume of water filled by Tap V
= 149240 - 56000
= 93240 cm
3 Rate in which Tap V fills the container
= 93240 ÷ 4
= 23310 cm3/min
23310 mℓ/min
= 23.31 ℓ/min
≈ 23.3 ℓ/min (Correct to 1 decimal place)
Answer(s): 23.3 ℓ/min