Question 825616
Let s be the number of students.
Let a be the number of adults.
Total number of people = s + a = 595.

Tickets for students are $3/student, so revenue from students = 3s dollars.
Tickets for adults are $5/adult, so revenue from adults = 5a dollars.
Total revenue = 3s + 5a = 1951.

Our two equations then are,
s + a = 595
3s + 5a = 1951
multiplying the 1st eqn by 3,
3s + 3a = 1785
3s + 5a = 1951
subtracting the 1st eqn from the  2nd eqn,
2a = 266
a = 133
s = 595 - 133 = 462
Number of adult tickets sold = 133
Number of student tickets sold = 466