Answer:
$2
Explanation:
Let the cost of a student's ticket be x.
If 800 tickets were sold and 450 tickets were full-price, therefore the total number of student's tickets = 800 - 450 =350.
We're told that each full-price ticket cost $7 each and the gate receipts were $3,850, our equation can then be written as;
[tex]\begin{gathered} 350x+(450\times7)=3850 \\ 350x+3150=3850 \\ 350x=3850-3150 \\ 350x=700 \\ x=\frac{700}{350} \\ \therefore x=2 \end{gathered}[/tex]