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**1. Finding a percentage of a given number:**

To find the percentage of a given number, multiply the number by the require percent.

Let the number \(= x\)

Required percent \(= p\)\(\%\)

Percentage of given number \(= p\)\(\%\) of \(x\)

\(=\) $\frac{p}{100}\times x$

**2. Finding the original number from its percent:**

Let original number \(= x\)

Required percent \(= p\)\(\%\)

Obtained percentage \(= y\)

Now \(p\)\(\%\) of \(x = y\)

$\frac{p}{100}\times x$ \(= y\)

\(x =\) $\frac{y}{p}\times 100$

**Original Number**\(=\) \(\frac{\text{Obtained Number}}{\text{percent}}\)\(\times100\)

**3. Finding how much percent one quantity is of another quantity:**

To find what percent of one quantity is of the other quantity if two quantities are given, we proceed as follows:

Let \(a\) and \(b\) are two quantities and we want to know 'what percent of '\(a\)' is '\(b\)'?

Let \(x\)\(\%\) of \(a\) is equal to \(b\) then:

$\begin{array}{l}\frac{x}{100}\times a=b\\ \\ x=\frac{b}{a}\times 100\end{array}$