Question 230267
You need to have 2 equations with 2 variables.

Let x=Number of student tickets, y=Number of Non-student tickets

Equation 1:  x+y=311
Equation 2:  0.50x + 1.50y = 385.50

To solve, I will use substitution by isolating for x in equation 1.

x = 311 - y

Substitute this into equation 2:

0.50(311-y) + 1.50y = 385.50
155.5 - 0.5y + 1.50y = 385.50
y=385.50 - 155.5
y=230

Find x by subbing y=230 into Equation 1:

x = 311 - 230
x = 81

The number of student tickets sold was 81, and non-student tickets was 230.