125t + 5.75t ≤ 685, and yes, you can purchase the tickets.
To determine how many tickets you can purchase, we need to solve the inequality:
125t + 5.75t + 20 ≤ 685
Combining like terms, we get:
130.75t + 20 ≤ 685
Subtracting 20 from both sides, we get:
130.75t ≤ 665
Dividing both sides by 130.75, we get:
t ≤ 5.08
Since you cannot purchase a fraction of a ticket, you can purchase a maximum of 5 tickets.