A number is increased by 25% and the resulting number is then decreased by 20%. The final number is what percent of the original number?
I know the answer is 100 but how do I show it?
A number is increased by 25% and the resulting number is then decreased by 20%. The final number is what percent of the original number?
I know the answer is 100 but how do I show it?
Dear donnagirl,
Suppose your number is x, then when it is increased by 25% the resulting number is,
$\displaystyle x+\frac{25x}{100}$
Then the result is decreased by 20% that is,
$\displaystyle \left(x+\frac{25x}{100}\right)-\frac{20}{100}\left(x+\frac{25x}{100}\right)=\frac {5x}{4}-\frac{1}{5}\left(\frac{5x}{4}\right)=x$
So the number is 100% of the original number.
Hope this will help you.