Question

At noon, a tank contained 10 cm of water. After several hours, it contained 7 cm of water. What is the percent decrease of water in the tank? Explain?

Answer 1

The tank decreased from 10 cm to 7 cm, so the tank lost 3 cm of water.

Out of the original 10 cm, the 3 cm that was lost is 30% of the 10 cm.

So there was a 30% decrease.

Answer 2

The percent decrease of water in the tank is 30%

Explanation:

A tank contained 10 cm of water.

After several hours, it contained 7 cm of water

So, decrease in water = 10 cm - 7 cm = 3 cm

The percent decrease of water in the tank =
`\frac{\text{Change in amount of water}}{\text{Initial amount}} * 100`

The percent decrease of water in the tank =
`(3)/(10) * 100`

=
`30`

Hence the percent decrease of water in the tank is 30%