Final answer:
The problem is solved by setting up an algebraic equation. After including Mark in the number of movie tickets and accounting for the fixed concession costs, it is calculated that there are 4 friends who went to the movies with Mark.
Step-by-step explanation:
The student's question involves a basic algebra problem in which they need to determine the number of friends who went to the movies with Mark. Since we know the total amount spent, the cost of movie tickets per person, and the amount spent on concessions, we can set up an equation to solve for the number of people.
Let x represent the number of friends who went to the movies with Mark. The cost for each person's movie ticket is $9, so the total cost for movie tickets is $9(x+1), as we include Mark in our calculation. They also spent $22 on concessions, which is a fixed amount. The total amount spent is $67. Therefore, we can create the following equation
9(x+1) + $22 = $67
Now, let's solve for x:
- 9(x+1) + 22 = 67
- 9x + 9 + 22 = 67
- 9x + 31 = 67
- 9x = 67 - 31
- 9x = 36
- x = 36 / 9
- x = 4
Therefore, there are 4 friends who went to the movies with Mark.