The figure shows an empty rectangular container with a capacity of 78 ℓ. The container has a height of 30 cm. Tap T filled the container at a rate of 2.9 ℓ per minute. Tap U drained water from the container at a rate of 1.4 ℓ per minute. Both taps were turned on for 10 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
78 ℓ = 78 x 1000 = 78000 mℓ
Base area of the container
=
Volumeheight =
7800030 = 2600 cm
2 (b)
Volume of water that filled the container per minute when both taps were turned on
= 2.9 - 1.4
= 1.5 ℓ
Volume of water that filled the container in 10 minutes when both taps were turned on
= 10 x 1.5
= 15 ℓ
Volume of water needed to fill the container
= 78 - 15
= 63 ℓ
Answer(s): (a) 2600 cm
2; (b) 63 ℓ