The figure shows an empty rectangular container with a capacity of 87 ℓ. The container has a height of 30 cm. Tap S filled the container at a rate of 3.5 ℓ per minute. Tap T drained water from the container at a rate of 1.9 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
87 ℓ = 87 x 1000 = 87000 mℓ
Base area of the container
=
Volumeheight =
8700030 = 2900 cm
2 (b)
Volume of water that filled the container per minute when both taps were turned on
= 3.5 - 1.9
= 1.6 ℓ
Volume of water that filled the container in 9 minutes when both taps were turned on
= 9 x 1.6
= 14.4 ℓ
Volume of water needed to fill the container
= 87 - 14.4
= 72.6 ℓ
Answer(s): (a) 2900 cm
2; (b) 72.6 ℓ