Question

Simon bought 5 boxes of cereal c and 2 gallons of nonfat milk m for $20.08. Terri bought 3 of the same boxes of cereal b and 3 gallons of nonfat milk m for $18.87. Based on this information, what is the cost of one gallon of milk?

Answer 1

Based on the information, the cost of one galon of milk is $3.79

Let us give a representation

Let the cost of a cereal box be $c and the cost of milk be $m

From the question, let us start with Simon

5 cereal boxes and 2 gallons of milk

That would be;

`5c\text{ + 2g = 20.08 }\ldots.(i)`

For Terri;

`\begin{gathered} 3c\text{ + 3g = 18.87} \\ \text{divide through by 3} \\ c\text{ + g = 6.29} \\ c\text{ = 6.29-g }\ldots\ldots..(ii) \end{gathered}`

We can proceed to substitute the second equation into the first

We have this as;

`\begin{gathered} 5(6.29-g)\text{ + 2g = 20.08} \\ 31.45-5g+2g\text{ = 20.08} \\ 31.45-20.08\text{ = 5g-2g} \\ 3g\text{ = 11.37} \\ g\text{ = }(11.37)/(3) \\ g\text{ = 3.79} \end{gathered}`