A total of 324 tickets were sold for the school play. They were either adult tickets or student tickets. The number of student tickets sold was three times the number of adult tickets sold. How many adult tickets were sold?
Let A be the number of adult tickets sold and S be the number of student tickets sold.
From the information given, we can set up the following system of equations:
A + S = 324
S = 3A
Substitute the second equation into the first equation:
A + 3A = 324
4A = 324
A = 81
Therefore, 81 adult tickets were sold.