Second equation: 228 total price includes 22dollar x adult and 15dollar x children ticket price. Write the equation: 228= 22A+15C (substitute above value for adult)
228= 22(11-C) + 15C 228= 242-22C+15C 228 - 242 = 7C 14 = 7C C= 2 (there are 2 children in the group)