Question

mimi had $174 to buy tickets to a concert. the adult tickets cost $10.50 and the student tickets cost $7.50. She bought 4 more student tickets than adult tickets. how many adult tickets did she buy?

Answer 1

Let the number of adult tickets be x, and that of students tickets be y, then
10.50x + 7.50y = 174 . . .(1)
y = x + 4 . . . . . . . . . . . . .(2)

Putting (2) into (1) gives: 10.5x + 7.5(x + 4) = 174
10.5x + 7.5x + 30 = 174
18x = 174 - 30 = 144
x = 144/18 = 8
Therefore, she bought 8 adult tickets.