Fill in the following contingency table and find the number of students who both go to the beach AND go to the mountains. \begin{tabular}{|l|l|l|l|} \hline Students & go to the mountains & do not go to the mountains & Total \\ \hline go to the beach & & & 36 \\ \hline do not go to the beach & & 21 & \\ \hline Total & 48 & & 95 \\ \hline \end{tabular}

Step 1 ：Given that the total number of students is 95.

Step 2 ：Given that the total number of students who go to the beach is 36.

Step 3 ：Given that the total number of students who go to the mountains is 48.

Step 4 ：Given that the number of students who do not go to the beach and do not go to the mountains is 21.

Step 5 ：Subtract the number of students who do not go to either the beach or the mountains from the total number of students to find the number of students who go to either the beach or the mountains: \(95 - 21 = 74\).

Step 6 ：Subtract the number of students who go to either the beach or the mountains from the sum of the number of students who go to the beach and the number of students who go to the mountains to find the number of students who go to both: \(36 + 48 - 74 = 10\).

Step 7 ：Final Answer: The number of students who both go to the beach AND go to the mountains is \(\boxed{10}\).