Which set of ordered pairs represents y as a function of x? A) {(2, 5), (3, 1), (2, 1), (4, 7)}
B) {(3, 2), (4, 3), (5, 2), (2, 6)}
C){(1, 3), (3, 5), (2, 5), (1, 6)}

Tom wants to order tickets online so that he and three of his friends can go to a water park the cost of the tickets is 16.00 per person there is also a 2.50 one-time service fee for ordering tickets online write an expression in term of n that represents the cost for n ordering tickets online