We can set-up a system of equations to find the number of adults. We know students and adults attended. We will let s be the number of students and a be the number of adults. Since 1,325 tickets were purchased, then s+a=1325.
We also know that a total of $3,169 was collected and adult tickets cost $5 each and students cost $1 each. We can write 1s+5a=3169.
We will solve by substituting one equation into the other. We first solve the first equation for s which is s=1325-a. Substitute s=1325-a into 1s+5a=3169. Simplify and isolate the variable a.
1(1325-a)+5a=3169
1325-a+5a=3169
1325+4a=3169
1325-1325+4a=3169-1325
4a=1844
a=461
This means that 461 adults attended and 864 students attended since 864+461=1325.