Question

A business supply store sells 10 pens for$8. What is the cost of 2 pens?
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Answer 1

`\begin{array}{ccll} pens&\$\\ \cline{1-2} 10 & 8\\ 2& x \end{array} \implies \cfrac{10}{2}=\cfrac{8}{x}\implies 5=\cfrac{8}{x}\implies 5x=8\implies x=\cfrac{8}{5}\implies x=1.6`