Chapter 7, Problem 20CT

To determine

To find: The percentage of the stamps in the collection depict historical events.

Answer to Problem 20CT

The percentage of the stamps in the collection depict historical events $32.5$ .

Explanation of Solution

Given information: Your friend has $480$ stamps in a collection. Of these, $156$ stamps depict historical events. What percent of the stamps in the collection depict historical events?

Calculation:

The total number of stamps is $480$ and the number of stamps which are depict historical events is $156$ .

Let, the percentage of the stamps is $x$ .

Therefore the relation is $=x\%\text{ of }480$ is $\mathrm{156......}(1)$

Hence, The percent $(\%)$ means ‘out of $100$ ’ and when dealing with percents the word ‘of’ means ‘times or to multiply’.

Let’s find the value of x from the equation $(1)$ ,

  $\begin{array}{c}x\%\text{ of 480}=156\\ \frac{x}{100}\times 480=156\\ x=\frac{156\times 100}{480}\\ x=\frac{156\times 10}{48}\\ x=\frac{39\times 10}{12}\\ x=\frac{13\times 10}{4}\\ x=32.5\end{array}$

Hence, The percentage of the stamps in the collection depict historical events $32.5$ .