A rectangular tank measuring 77 cm by 58 cm by 35 cm was to be filled with water by two taps, C and D. Tap C which fills the tank at a rate of 8 ℓ per minute was first turned on for 3 minutes before Tap D was turned on as well. If the tank was filled to the brim in a total of 5 minutes from the time when Tap C was first turned on, what is the rate at which Tap D fills the tank? Give your answer in ℓ per minute correct to 1 decimal place.
Total volume of the tank
= 77 x 58 x 35
= 156310 cm
3 1 ℓ = 1000 cm
3 8 ℓ = 8000 cm
3 Volume of water filled by Tap C
= 8000 x 5
= 40000 cm
3 Volume of water filled by Tap D
= 156310 - 40000
= 116310 cm
3 Rate in which Tap D fills the tank
= 116310 ÷ 2
= 58155 cm3/min
58155 mℓ/min
= 58.155 ℓ/min
≈ 58.2 ℓ/min (Correct to 1 decimal place)
Answer(s): 58.2 ℓ/min