<h2>
Systems of Equations</h2>
To form a system of equation from a word problem, we must recognize different variables to form different equations.
<h2>Solving the Question</h2>
Let <em>a</em> represent the number of child tickets.
Let <em>b</em> represent the number of adult tickets.
We're given:
- 1a = $6.20
- 1b = $9.40
- a and b in total is 163
- Total sales = $1221.80
Because we're given that a and b in total is 163, we can form the following equation:

We're also given that the total sales made is $1221.80. Because we know that 1a = $6.20 and 1b = $9.40, we can also form the following equation:

Here are our two equations:


<h3>Solving the System of Equations</h3>
We can solve using the method of elimination. Multiply both sides by 6.2 in the first equation:

Subtract this new equation from the second equation to cancel out <em>a</em>:

Solve for <em>b</em>:

Therefore, the number of adult tickets sold is 66.
<h2>Answer</h2>
66