The figure shows an empty rectangular container with a capacity of 38 ℓ. The container has a height of 20 cm. Tap P filled the container at a rate of 2.5 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 8 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
38 ℓ = 38 x 1000 = 38000 mℓ
Base area of the container
=
Volumeheight =
3800020 = 1900 cm
2 (b)
Volume of water that filled the container per minute when both taps were turned on
= 2.5 - 1.4
= 1.1 ℓ
Volume of water that filled the container in 8 minutes when both taps were turned on
= 8 x 1.1
= 8.8 ℓ
Volume of water needed to fill the container
= 38 - 8.8
= 29.2 ℓ
Answer(s): (a) 1900 cm
2; (b) 29.2 ℓ