Question

This is a pond in the shape of a prism. It is completely full of water. Colin uses a pump to empty the pond. The level goes down by 30cm in the first 30 minutes. Work out how many minutes Colin has to wait for the pond to completely empty.

Answer 1

Colin needs to wait for 30 times the height of the pond in minutes for it to completely empty.

To find out how many minutes Colin has to wait for the pond to completely empty, we can use the information given. In the first 30 minutes, the water level goes down by 30cm.

This means that in 1 minute, the water level goes down by 1cm. To empty the entire pond, which is the height of the prism, Colin will have to wait for 30 times the height of the pond in minutes.

If we assume that the height of the pond is h cm, then Colin has to wait for 30h minutes for the pond to completely empty.