Ex.8.3 Q3 Compairing Quantities - NCERT Maths Class 7

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The population of a city decreased from \(25,000\) to \(24,500.\) Find the percentage decrease.

 Video Solution
Comparing Quantities
Ex 8.3 | Question 3

Text Solution

What is Known?

The change in the population of a city (from \(25,000\) to \(24,500\))

What is Unknown?

The percentage decrease


The decrease in population can be calculated by subtracting earlier (initial) population from present (final) population and percentage decrease in population can be obtained using the formula

 Percentage decrease   

\[\begin{align}=\frac{{{\text{Change}}\;{\text{in}}\;\;{\text{quantity}}}}{{{\text{Initial}}\;{\text{quantity}}\;}}{\rm{ \times 100}}\end{align}\]


 Decrase in city population 

\[\begin{align}&= 25000 - 24500\\&= 500\end{align}\]

Percentage decrease 

\[\begin{align}&= \,\frac{{{\text{Change}}\;{\text{in}}\;\;{\text{population}}}}{{{\text{Initial}}\;{\text{population}}\;}}{\rm{ \times 100}}\\&= \,\frac{{{\text{500}}}}{{{\text{25000}}}}{\rm{ \times 100}}\\&= \,{\text{2% }}\end{align}\]