A rectangular tank measuring 73 cm by 60 cm by 28 cm was to be filled with water by two taps, U and V. Tap U which fills the tank at a rate of 6 ℓ per minute was first turned on for 2 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
= 73 x 60 x 28
= 122640 cm
3 1 ℓ = 1000 cm
3 6 ℓ = 6000 cm
3 Volume of water filled by Tap U
= 6000 x 5
= 30000 cm
3 Volume of water filled by Tap V
= 122640 - 30000
= 92640 cm
3 Rate in which Tap V fills the tank
= 92640 ÷ 3
= 30880 cm3/min
30880 mℓ/min
= 30.88 ℓ/min
≈ 30.9 ℓ/min (Correct to 1 decimal place)
Answer(s): 30.9 ℓ/min