Answer:
100 children and 70 adult tickets were sold.
Explanation:
Let x represent number of adult tickets and y represent number of children tickets.
We have been given that tickets for a school carnival cost $10 for adults, so cost of x tickets would be
.
Since cost of each ticket for children is $5, so cost of y tickets would be
.
We are told that last Saturday carnival sold tickets worth a total of $1200. We can represent this information in an equation as:

We are also told that number of total tickets sold was 170. We can represent this information in an equation as:

Now, we will use substitution method to solve system of linear equations. From equation (2), we will get:

Upon substituting
in equation (1), we will get:







Therefore, 100 children tickets were sold.
To find number of children tickets sole, we will substitute
in equation (2).



Therefore, 70 adult tickets were sold.