The figure shows an empty rectangular container with a capacity of 45 ℓ. The container has a height of 30 cm. Tap P filled the container at a rate of 2.8 ℓ per minute. Tap Q drained water from the container at a rate of 1.4 ℓ per minute. Both taps were turned on for 7 minutes and then turned off.
- What is the base area of the container?
- After both taps were turned off, how much more water is needed to fill the container completely? Give your answer in litres.
(a)
1 ℓ = 1000 mℓ
45 ℓ = 45 x 1000 = 45000 mℓ
Base area of the container
=
Volumeheight =
4500030 = 1500 cm
2 (b)
Volume of water that filled the container per minute when both taps were turned on
= 2.8 - 1.4
= 1.4 ℓ
Volume of water that filled the container in 7 minutes when both taps were turned on
= 7 x 1.4
= 9.8 ℓ
Volume of water needed to fill the container
= 45 - 9.8
= 35.2 ℓ
Answer(s): (a) 1500 cm
2; (b) 35.2 ℓ