Question

It costs $2.85 to buy 3/4 lb of plums. how much would it cost to purchase 9 pounds of plums?

Answer 1

`\begin{array}{ccll} lbs&\$\\ \cline{1-2} (3)/(4)&2.85\\[1em] 9&x \end{array}\implies \cfrac{~~ (3)/(4)~~}{9}=\cfrac{2.85}{x}\implies \cfrac{~~ (3)/(4)~~}{(9)/(1)}=\cfrac{2.85}{x}\implies \cfrac{3}{4}\cdot \cfrac{1}{9}=\cfrac{2.85}{x} \\\\\\ \cfrac{1}{4}\cdot \cfrac{1}{3}=\cfrac{2.85}{x}\implies \cfrac{1}{12}=\cfrac{2.85}{x}\implies x = 34.2`