Question

A number $x$ is mistakenly divided by $10$ instead of being multiplied by $10$. What is the percentage error in the result?

• A. $-99\%$
• B. $+99\%$
• C. $-100\%$
• D. $+100\%$

Answer 1

The correct option is A $-99\%$

In the given question the number obtained after dividing $x$ be $10$ is $\frac{x}{10}$.
After the correction, we get $10x$
Now, the percentage error is given by $\frac{\frac{x}{10}-10x}{10x}\times 100$

$=\frac{\frac{-99x}{10}}{10x}\times 100=-99=\frac{-99x}{100x}\times 100$

Hence, the percentage error is $-99\%$