On Tuesday, 525 people bought tickets to the county fair. Tickets cost $7 for adults and $3 for children. The total revenue from ticket sales on Tuesday was $2775. The system of equations below represents the number of people and total sales for the county fair on Tuesday, where x represents the number of child tickets and y represents the number of adult tickets.




How many adult tickets were sold on Tuesday?

A.340
B.280
C.225
D.300