Answer: C=222 and A =120
Explanation:
Let C be the number of children tickets and A be the number of adult tickets.
Then, According to the question, we have the following system:-

Multiply equation (1) by 5 on both sides ,we get

Eliminate equation (3) from equation (2), we get

Substitute the value of A in (1), we get
Hence, the number of children tickets sold = 222 and the number of adult tickets sold =120