Question:
A total of $1332.50 was collected from the sales of adult and child tickets to a concert. $635.50 more was collected from the sale of the adult tickets than the child tickets. Each child ticket cost $3.50 less than an adult ticket. There were twice as many adult tickets sold as the child tickets. Find the total number of children who went to the concert.

Solution:
![P6 ACS 2018 Paper2 Q11 [Sol]](https://i0.wp.com/sgprimaths.com/wp-content/uploads/2019/06/P6-ACS-2018-Paper2-Q11-Sol.jpg?resize=640%2C480&ssl=1)