Answer:
A senior citizen costs $8
Explanation:
Represent senior citizens with S and children with C.
The first day is represented as:

The second day is represented as:

Required
Solve for C and S
Make C the subject in the first equation

Substitute 38 - 3S for C in the second equation


Collect Like Terms


Divide through by -3

Recall that:




Hence, a senior citizen costs $8