A rectangular tank measuring 74 cm by 58 cm by 40 cm was to be filled with water by two taps, D and E. Tap D which fills the tank at a rate of 5 ℓ per minute was first turned on for 4 minutes before Tap E was turned on as well. If the tank was filled to the brim in a total of 5 minutes from the time when Tap D was first turned on, what is the rate at which Tap E fills the tank? Give your answer in ℓ per minute correct to 1 decimal place.
Total volume of the tank
= 74 x 58 x 40
= 171680 cm
3 1 ℓ = 1000 cm
3 5 ℓ = 5000 cm
3 Volume of water filled by Tap D
= 5000 x 5
= 25000 cm
3 Volume of water filled by Tap E
= 171680 - 25000
= 146680 cm
3 Rate in which Tap E fills the tank
= 146680 ÷ 1
= 146680 cm3/min
146680 mℓ/min
= 146.68 ℓ/min
≈ 146.7 ℓ/min (Correct to 1 decimal place)
Answer(s): 146.7 ℓ/min