Ava and Greg are selling cookies and popcorn to raise money for a school trip. Ava sold 10 boxes of cookies and 8 bags of popcorn and raised $102. Greg sold 4 boxes of cookies and 12 bags of popcorn and raised $98. How much is a bag of popcorn?

Let x represent number of boxes of cookies and y represent popcorn bags.

We have been given that Ava sold 10 boxes of cookies and 8 bags of popcorn and raised $102. We can represent this information in an equation as:

We are also told that Greg sold 4 boxes of cookies and 12 bags of popcorn and raised $98. We can represent this information in an equation as:

Now we will use substitution method to solve our system of equations.

Form equation (1), we will get:

Upon substituting this value in equation (2), we will get:

Therefore, each bag of popcorn costs $6.5.