Answer:
14.
Explanation:
1) if mr. Oliveros spent 10$ for his ticket, then the rest sum of his money is 45-10=35$;
2) according to the condition mr. Oliveros spends 35$ for unknown number tickets for students, where 2.5$ for each student. Using this conditiion it is possible to calculate the number of student tickets:
35/2.5=14.