Word problem help. How to find the answer.

Question

There are 68 cookies. There are 18 fewer oatmeal raisin cookies than chocolate chip cookies. How many chocolate chip cookies are there?

Answer 1

Hi Sara, let or represent the oatmeal raisin cookies and cc represent the chocolate chip cookies. Then we can build an equation to represent the total cookies:

 

or + cc = 68

 

But, we know that there is 18 fewer oatmeal raisin cookies than chocolate chip cookies. We can represent this as:

 

or + 18 = cc

 

Substitute for cc in the original equation:

 

or + (or + 18) = 68

 

2or + 18 = 68

 

2or = 50

 

or = 25

 

cc = or + 18

 

cc = 25 + 18

 

cc = 43

 

There are 25 oatmeal raisin cookies and 43 chocolate chip cookies.

 

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