Tickets to a school play were sold for $3.50 for each adult and $2.00 for each child. A total of 325 people attended the play and the total amount that was taken in was $875. How many of each kind of ticket was sold.
number of adult tickets ---- x
number of children's tickets ---- 325-x
solve for x .....
3.5x + 2(325-x) = 875