Answer:
30%.
Step-by-step explanation:
We have been given that at noon a tank contains 10 cm of water after several hours it contains 7 cm of water.
To find the decrease percent we will use formula:
[tex]\text{Decrease percent}=\frac{\text{Original value-new value}}{\text{Original value}}\times 100[/tex]
Upon substituting our given values in above formula we will get,
[tex]\text{Decrease percentage of water in the tank}=\frac{10-7}{10}\times 100[/tex]
[tex]\text{Decrease percentage of water in the tank}=\frac{3}{10}\times 100[/tex]
[tex]\text{Decrease percentage of water in the tank}=3\times 10=30[/tex]
Therefore, the percentage decrease of water in the tank is 30%.
