Question

Divide 3420 into two parts such that one part is 28 percent more than the other​

Answer 1

x = the other part

let's first find how much is 28% of "x"

`\begin{array}c \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{28\% of x}}{\left( \cfrac{28}{100} \right)x}\implies 0.28x`

so whatever the first part is, is "x" plus 0.28x, or namely 1.28x, and we know their sum is 3420

`x+1.28x=3420\implies 2.28x=3420\implies x=\cfrac{3420}{2.28} \\\\\\ \boxed{x=1500}\hspace{5em}\stackrel{ 3420~~ - ~~1500 }{\boxed{1.28x=1920}}`