A group of friends attends a play. They buy 5 adult tickets and 3 child tickets for a total cost of $120. Another group buys 3 adult tickets and 6 child tickets for a total cost of $144. Let represent the price of an adult ticket and represent the price of a child ticket. Which system of linear equations represents this situation?
5a + 3c = 120
3a + 6c = 144
5a + 6c = 120
3a + 3c = 144
5a + 3c = 144
3a + 6c = 120
3a + 5c = 120
6a + 3c = 144
