A rectangular container measuring 90 cm by 51 cm by 25 cm was to be filled with water by two taps, R and S. Tap R which fills the tank at a rate of 6 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 6 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 container
= 90 x 51 x 25
= 114750 cm
3 1 ℓ = 1000 cm
3 6 ℓ = 6000 cm
3 Volume of water filled by Tap R
= 6000 x 6
= 36000 cm
3 Volume of water filled by Tap S
= 114750 - 36000
= 78750 cm
3 Rate in which Tap S fills the container
= 78750 ÷ 3
= 26250 cm3/min
26250 mℓ/min
= 26.25 ℓ/min
≈ 26.3 ℓ/min (Correct to 1 decimal place)
Answer(s): 26.3 ℓ/min