Find How much each box of chocolate chip cookies and how much was each box of oatmeal cookies?

Question

Michael and Stephanie are selling cookies for a school fundraiser. Customers can buy boxes of either chocolate chip or oatmeal cookies. Michael sold 14 boxes of chocolate chip cookies and 6 boxes of oatmeal cookies for a total of $160. Stephanie sold 12 boxes of chocolate chip cookies and 12 boxes of oatmeal cookies for a total of $192. How much was each box or chocolate chip cookies and how much was each box of oatmeal cookies?

Your answer

Answer 1

Answer 2

The two unknowns are the price of chocolate chip boxes and the price of oatmeal cookie boxes.

So let c = the price of chocolate chip boxes and m = the price of oatmeal cookie boxes.

14 boxes of chocolate chips and 6 boxes of oatmeal cookies add up to $160

Therefore,

14c + 6m = 160. (c and m are in dollars, since the prices in the problem are in dollars)

Similarly, 12 boxes of chocolate chips and 12 boxes of oatmeal cookies add up to $192 gives the equation:

12c + 12m = 192. We'll divide each term in this equation by 12 to get: c + m = 16

Now we have two equations:

14c + 6m = 160

c + m = 16.

Do you think you can solve the systems of equations?

Answer 3

Here you would perform elimination to determine the first variable then plug in to find the other.

In this problem we will set (o) for oatmeal cookies and (C) for chocolate chip cookies. In looking at the equation we get these two base equations.

14C+6O=160

12C+12O=192

After getting these two equations, we want to multiply the first equation by -2 so we cancel out (o). This gives us

-28c-12o=-320

12C+12O=192

We now cancel out the 12 and we now get

16C=128

whicy gives C a value of $8 per box of chocolate chip cookies.

Now we can plug 8 in either equation to determine the cost of Oatmeal cookies.

12(8)+12(O)=192

96+12O=192

12O=96

O=$8 per box

Now we plug both values in to double check our answer

12(8)+12(8)=192

192=192

so we are correct

Answer 4

14c + 6o = 160

12c + 12o = 192

Can you solve for c or o and answer?