A rectangular tank measuring 87 cm by 56 cm by 26 cm was to be filled with water by two taps, R and S. Tap R which fills the tank at a rate of 8 ℓ per minute was first turned on for 3 minutes before Tap S was turned on as well. If the tank was filled to the brim in a total of 5 minutes from the time when Tap R was first turned on, what is the rate at which Tap S fills the tank? Give your answer in ℓ per minute correct to 1 decimal place.
Total volume of the tank
= 87 x 56 x 26
= 126672 cm
3 1 ℓ = 1000 cm
3 8 ℓ = 8000 cm
3 Volume of water filled by Tap R
= 8000 x 5
= 40000 cm
3 Volume of water filled by Tap S
= 126672 - 40000
= 86672 cm
3 Rate in which Tap S fills the tank
= 86672 ÷ 2
= 43336 cm3/min
43336 mℓ/min
= 43.336 ℓ/min
≈ 43.3 ℓ/min (Correct to 1 decimal place)
Answer(s): 43.3 ℓ/min