Answer:
Step-by-step explanation:
The given price relations allow us to write two equations involving the prices of the tickets. Those can be solved to find ticket prices.
Let s and c represent the prices of senior and child tickets respectively. Then the described sales can be written as ...
 3s +c = 38 . . . . first day's sales
 3s +2c = 52 . . . second day's sales
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Subtracting the first equation from the second eliminates the s variable and gives the price of a child ticket:
 (3s +2c) -(3s +c) = (52) -(38)
 c = 14 . . . . . simplify
Then the price of a senior citizen ticket can be found using the first equation:
 3s +14 = 38 . . . . . substitute for c
 3s = 24 . . . . . . . subtract 14
 s = 8 . . . . . . . divide by 3
The price of a senior citizen ticket is $8; the price of a child ticket is $14.