A charity event sold two types of tickets: standard tickets for $\$12.50$ each and VIP tickets for $\$20.00$ each. The total revenue from ticket sales was $\$750$. The equation $12.50S+20.00V=750$ models this situation, where $S$ is the number of standard tickets sold and $V$ is the number of VIP tickets sold. If the number of VIP tickets sold was 15, how many standard tickets were sold?