A rectangular container measuring 78 cm by 58 cm by 33 cm was to be filled with water by two taps, X and Y. Tap X which fills the tank at a rate of 8 ℓ per minute was first turned on for 3 minutes before Tap Y was turned on as well. If the tank was filled to the brim in a total of 5 minutes from the time when Tap X was first turned on, what is the rate at which Tap Y fills the tank? Give your answer in ℓ per minute correct to 1 decimal place.
Total volume of the container
= 78 x 58 x 33
= 149292 cm
3 1 ℓ = 1000 cm
3 8 ℓ = 8000 cm
3 Volume of water filled by Tap X
= 8000 x 5
= 40000 cm
3 Volume of water filled by Tap Y
= 149292 - 40000
= 109292 cm
3 Rate in which Tap Y fills the container
= 109292 ÷ 2
= 54646 cm3/min
54646 mℓ/min
= 54.646 ℓ/min
≈ 54.6 ℓ/min (Correct to 1 decimal place)
Answer(s): 54.6 ℓ/min