Number of tickets: T. Number of customers: c Initially the number of tickets is T0=150, when the group hasn't sold any tickets (c=0). Then the graph must begin with c=0 and T=150. Point=(0,150). Possible options: Graph above to the right and graph below to the left. They sell the tickets in pack of three tickets per customer c, then each time they sell a pack of three tickets to a customer, the number of tickets is reduced by 3 (-3c). Then the number of tickets, T, the group has left after selling tickets to c customers is: T=150-3c→T=-3c+150
For T=0→-3c+150=0→150=3c→150/3=c→c=50. The graph must finish with c=50, T=0. Final point=(c,T)=(50,0)
Answer: The correct graph is above to the right, beginning on vertical axis with T=150 and finishing on horizontal axis with c=50. The correct equation is T=-3c+150
