Question

twelve large bottles of water cost 9 dollars jaw many for 3$ what's the cost per bottle how much would 7 bottles of water cost

Answer 1

12 large bottles = $9

$a.\text{ number of bottles one can buy for \ 3 = }\frac{12\times3}{9}=\frac{36}{9}=4\text{ bottles}$$\begin{gathered} b\text{. 4 bottles = \ 3} \\ 1\text{ bottle =?} \\ \text{cost per bottle = \ }\frac{3}{4}=0.75\text{ dollars} \end{gathered}$$\begin{gathered} c\text{. 12 bottles = \ 9} \\ 7\text{ bottles = ?} \\ \text{cost of 7 bottles = }\frac{9\times7}{12}=\frac{63}{12}=5.25\text{ dollars} \end{gathered}$