PLEASE HELP ME I REALLY NEED TO PASS THIS TEST
Beth bought 15 tickets to a movie, where adult tickets cost $8.00 and senior citizen tickets cost $6.00. She spent a total of $108. Which system of equations will determine the number of adult tickets, a, and the number of senior citizen tickets, s, Beth purchased?

a + s = 15

a + s = 108


a + s = 15

6a + 8s = 108


a + s = 15

8a + 6s = 108



a + s = 108

6a + 8s = 15