Answer: Therefore, we purchased 4 adult tickets and 7 child's tickets.
Explanation:
Through the information provided, we set up a system equation:
a + c = 11
7.50a + 5.00c = 65
By the first equation, we convert it into a form, then we get a = 11 - c. Then we plug in the a = 11 - c to the second equation:
7.50(11 - c) + 5.00c = 65
82.5 - 7.50c + 5.00c = 65
82.5 - 2.50c = 65
- 2.50c = 65 - 82.5
- 2.50c = - 17.5
c = - 17.5/- 2.50
c = 7
And we plug c = 7 back into the first equation, which is a + c = 11.
a + c = 11
a + 7 = 11
a = 11 - 7
a = 4
Therefore, we purchased 4 adult tickets and 7 child's ticket.