rxs0005 wrote:

John buys koolaid for 12$ at a local store. If he bought it at the wholesale store he would get an extra liter of koolaid for the same cost. Also the koolaid is 1$ cheaper per liter at the wholesale store. what is the price per liter of the koolaid at the local store

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Let's say John bought x litres of koolaid from the local store.

x liters-> $12

1 liter -> 12/x

Wholesale store:

(x+1) liters -> $12

1 liter -> 12/(x+1)

12/(x+1) is $1 less than 12/x

\(\frac{12}{x+1}+1=\frac{12}{x}\)

\(\frac{13+x}{x+1}=\frac{12}{x}\)

\(13x+x^2=12x+12\)

\(x^2+x-12=0\)

\(x^2+4x-3x-12=0\)

\(x(x+4)-3(x+4)=0\)

\((x-3)(x+4)=0\)

\(x=3 \hspace{2} OR \hspace{2} x=-4\)

Quantity of koolaid can't be negative.

\(x=3\)

John bought 3 liters of koolaid from the local store for $12

Price per liter = 12/x = 12/3 = $4

Ans: "B"

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