Answer:
The number of adult ticket = 86
Step-by-step explanation:
Let the number of adult tickets be x
The number of child ticket = 149 - x
x*9.20 + (149-x)*5.50 = $1137.70
9.2x + 149*5.5 -5.5x = 1137.70
3.7x + 819.5 = 1137.70
3.7x = 1137.70 - 819.50
3.7x = 318.2
x = 318.2/3.7
x = 86
The number of adult ticket = 86
The number of child ticket = 149 - 86 = 63