Question

Lana has $60. She spends 80% of the money. She then invests the remaining and earns a profit of 80%. How much money does she now have?

Answer 1

so she spent 80% of 60 bucks, so 100% - 80% = 20%, so she only has 20% of 60, then she earned 80% of those 20% of 60, hmmm

`\begin{array}ll \cline{1-1} \textit{\textit{\LARGE a}\% of \textit{\LARGE b}}\\ \cline{1-1} \\ \left( \cfrac{\textit{\LARGE a}}{100} \right)\cdot \textit{\LARGE b} \\\\ \cline{1-1} \end{array}~\hspace{5em}\stackrel{\textit{20\% of 60}}{\left( \cfrac{20}{100} \right)60}\implies 12 ~\hfill~\stackrel{\textit{80\% of 12}}{\left( \cfrac{80}{100} \right)12}\implies 9.6 \\\\\\ ~\hfill~\underset{ \textit{Lana has now} }{\stackrel{ 12~~ + ~~9.6 }{\text{\LARGE 21.6}}}~\hfill~`