Answer this question pls

14 pointslet x be the seats in the small van and y the seats in the large van. how many seats does the large van have? a company uses two vans to transport worker from a free parking lot to the workplace between 7: 00 and 9: 00a.m. one van has 9 more seats than the other. the smaller van makes two trips every morning while the larger one makes only one trip. the two vans can transport 69 people, maximum.how many seats does the larger van have?

How to do this , and can some one explain

The holiday party will cost $160 if 8 people attend.if there are 40 people who attend the party, how much will the holiday party cost