Let the price of an adult ticket is x and a child ticket is y .
from the question ,

Multiply 2 in eq (ii)

On adding eq (iii) and (i)

we get ,

putting y in eq (i)

The value of x = 17.5 and y = 9.5
Hence , The price of an adult ticket is 17.5 and the price of a child ticket is 9.5 .