A rectangular tank measuring 75 cm by 51 cm by 24 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 5 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
= 75 x 51 x 24
= 91800 cm
3 1 ℓ = 1000 cm
3 7 ℓ = 7000 cm
3 Volume of water filled by Tap U
= 7000 x 5
= 35000 cm
3 Volume of water filled by Tap V
= 91800 - 35000
= 56800 cm
3 Rate in which Tap V fills the tank
= 56800 ÷ 2
= 28400 cm3/min
28400 mℓ/min
= 28.4 ℓ/min
≈ 28.4 ℓ/min (Correct to 1 decimal place)
Answer(s): 28.4 ℓ/min