Question

candy selling at $6. per pound will be mixed with candy $9. per pound. how many pounds of the more expensive candy are needed to produce a 15 pound mixture fbaf sales for $7. per pound

Answer 1

Let's use the variable x to represent the amount of $6 candy bought and y to represent the amount of $9 candy bought.

If the final mixture has 15 pounds, we have the equation:

`x+y=15`

Then, the final price is $7 per pound, so we can write the equation:

`x\cdot6+y\cdot9=15\cdot7`

Solving this system, we have:

`\begin{gathered} \begin{cases}x+y=15 \\ 6x+9y=105\end{cases} \\ \begin{cases}-6x-6y=-90 \\ 6x+9y=105\end{cases} \\ -6x-6y+(6x+9y)=-90+105 \\ 3y=15 \\ y=5 \end{gathered}`

So the number of pounds of the expensive candy if 5, therefore the correct option is A.