Question

When $x\%$ of a number is added to $75$, the result is the number again. If the number is $300$, then $x$ is:

• A. $45$
• B. $55$
• C. $65$
• D. $75$

Answer 1

The correct option is D $75$

Let the number be $n$.

Then, $x$% of $n+75=n$

$\frac{x}{100}\times n+75=n$

$x=\frac{(n-75)100}{n}$

Given, $n=300$

$x=\frac{225\times 100}{300}=75$

$\therefore x=75$