Answer:
69 children, 57 adults
Step-by-step explanation:
Let a = number of adults and c = number of children.
a + c = 126---------------->4a + 4c = 504
4a + 2.25c = 383.25-->4a + 2.25c = 383.25
----------------------------
1.75c = 120.25
c = 69, a = 57