The figure shows an empty rectangular container with a capacity of 66 ℓ. The container has a height of 30 cm. Tap D filled the container at a rate of 2.5 ℓ per minute. Tap E drained water from the container at a rate of 1.4 ℓ per minute. Both taps were turned on for 9 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
66 ℓ = 66 x 1000 = 66000 mℓ
Base area of the container
=
Volumeheight =
6600030 = 2200 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 9 minutes when both taps were turned on
= 9 x 1.1
= 9.9 ℓ
Volume of water needed to fill the container
= 66 - 9.9
= 56.1 ℓ
Answer(s): (a) 2200 cm
2; (b) 56.1 ℓ