Question

3 oz of cinnamon cost $2.40 if there are 16 oz in 1 pound how much does cinnamon cost per pound

Answer 1

namely, if 3 oz costs $2.40, how much is it for 16 oz?

$\bf \begin{array}{ccll} oz&\ \\ \cline{1-2} 3&2.40\\ 16&x \end{array}\implies \cfrac{3}{16}=\cfrac{2.40}{x}\implies x=\cfrac{16\cdot 2.40}{3}\implies x=12.8$