Let price of adult ticket is $x
And price of child ticket is $y
So we can make two equations using the given data


Now we can use eliminator method to solve the two equations
Multiply first equation by 2 and second equation by -3




now add both the equations so we get

combine the like terms

Divide both sides by -1

Plug y=17 in any one of the equations to solve for x


Subtract 68 from both sides

Divide both sides by 3

So x=18 and y=17
So
Price of adult ticket= $18
Price of child ticket = $17