Answer:
The number of adult tickets sold was 5
Explanation:
Let
x ----> the number of adult tickets
y ----> the number of child tickets
we know that

isolate the variable y
----> equation A
----> equation B
Solve the system by substitution
substitute equation A in equation B

solve for x
apply distributive property left side

combine like terms

subtract 24 both sides


Divide by 2.50 both sides

therefore
The number of adult tickets sold was 5