Question

15 is what % less than 20

Answer 1

if we take 20(origin amount) as the 100%, what's 15 off of it in percentage?

`\begin{array}{ccll} amount&\%\\ \cline{1-2} 20 & 100\\ 15& x \end{array} \implies \cfrac{20}{15}~~=~~\cfrac{100}{x} \\\\\\ \cfrac{ 4 }{ 3 } ~~=~~ \cfrac{ 100 }{ x }\implies 4x=300\implies x=\cfrac{300}{4}\implies x=75 \\\\[-0.35em] ~\dotfill\\\\ \textit{15 is 75\% of 20, so is }\text{\LARGE 25\%}\textit{ less than 20}`