The first thing we must do for this case is to define variables.
We have then:
x: price of adult's ticket
y: price of child's ticket
We now write the system of equations:
![3x + 4y = 87 2x + 3y = 62](https://img.qammunity.org/2019/formulas/mathematics/middle-school/f5u4p8563nbqti5rt3drod9ysc61ig5yem.png)
Solving the system of equations we have:
x = 13 $
y = 12 $
Answer:
the price of adults ticket and price of child's ticket are $ 13 and $ 12, respectively