6 adult were sold for each 28 students ticket sold.
The ratio of adult to student ticket sold is 6:28 = 6/28 = 3/14
The number of student tickets sold is 252. Tha dult ticket can be calculated below
[tex]\begin{gathered} \text{28 students}=6\text{ adults} \\ 252\text{ students= ?} \\ \text{ Number of adult ticket sold=}\frac{252\times6}{28}=\frac{1512}{28}=54\text{ adult ticket} \\ \text{Total ticket sold = 54 adult ticket +252 student ticket=}306 \end{gathered}[/tex]