At the movie theater, child admission is $5.30 and adult admission is $9.50. On Tuesday, 158 tickets were sold for a total sales of $1198.60. How many adult tickets were sold that day?

Answer 1

If a adult tickets were sold, then the rest (158-a) were child tickets. SO now just add up the sales and solve for a.
9.50a + 5.30(158-a) = 1198.60