Question

Find the percent change from 84 to 63.

Answer 1

Answer:

-25%

20 characters

Answer 2

so the difference is 84 - 63 = 21.

if we take 84 to be the 100%, what is 21 off of it in percentage?

$\bf \begin{array}{ccll} amount&\%\\ \cline{1-2} 84&100\\ 21&x \end{array}\implies \cfrac{84}{21}=\cfrac{100}{x}\implies 4=\cfrac{100}{x}\implies 4x=100 \\\\\\ x=\cfrac{100}{4}\implies x=25$