For the high school's production of "Grease," 315 tickets were sold. The cost of a student ticket, s, was $5; the cost of all other tickets, t, was $8. The total income from ticket sales equaled $2211. The system of equations below can be used to determine the number of each type of ticket sold. s+t=315 55 + 8 = 2211 How many student tickets were sold?