some one please help me this is my final question i think i have the right answers but im not sure

Suppose that there are two types of tickets to a show: advance and same-day. The combined cost of one advance ticket and one same-day ticket is 35
. For one performance, 15
advance tickets and 40
same-day tickets were sold. The total amount paid for the tickets was 900
. What was the price of each kind of ticket?