The figure shows an empty rectangular tank with a capacity of 48 ℓ. The tank has a height of 30 cm. Tap F filled the tank at a rate of 2.9 ℓ per minute. Tap G drained water from the tank at a rate of 1.6 ℓ per minute. Both taps were turned on for 27 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
48 ℓ = 48 x 1000 = 48000 mℓ
Base area of the tank
=
Volumeheight =
4800030 = 1600 cm
2 (b)
Volume of water that filled the tank per minute when both taps were turned on
= 2.9 - 1.6
= 1.3 ℓ
Volume of water that filled the tank in 27 minutes when both taps were turned on
= 27 x 1.3
= 35.1 ℓ
Volume of water needed to fill the tank
= 48 - 35.1
= 12.9 ℓ
Answer(s): (a) 1600 cm
2; (b) 12.9 ℓ