The figure shows an empty rectangular tank with a capacity of 35 ℓ. The tank has a height of 25 cm. Tap S filled the tank at a rate of 2.5 ℓ per minute. Tap T drained water from the tank at a rate of 1.3 ℓ per minute. Both taps were turned on for 24 minutes and then turned off.
- What is the base area of the tank?
- After both taps were turned off, how much more water is needed to fill the tank completely? Give your answer in litres.
(a)
1 ℓ = 1000 mℓ
35 ℓ = 35 x 1000 = 35000 mℓ
Base area of the tank
=
Volumeheight =
3500025 = 1400 cm
2 (b)
Volume of water that filled the tank per minute when both taps were turned on
= 2.5 - 1.3
= 1.2 ℓ
Volume of water that filled the tank in 24 minutes when both taps were turned on
= 24 x 1.2
= 28.8 ℓ
Volume of water needed to fill the tank
= 35 - 28.8
= 6.2 ℓ
Answer(s): (a) 1400 cm
2; (b) 6.2 ℓ