The ages of students at a school were recorded. a) How many students are younger than 10? b) Which class occurred the most? c) What percentage of students were older than 15?

\[\begin{array}{ | c | c | c| } \hline \quad \text{Class} \quad & \quad \text{Class Centre} \quad & \quad \text{Frequency } \quad \\ \hline 4-6& 5&98\\ \hline 7-9 & 8&198\\ \hline 10-12& 11&212\\ \hline 13-15& 14&245\\ \hline 16-18& 17&204\\ \hline & \text{Total}& 957\\ \hline \end{array}\]