A music concert was attended by 450 people. Adult tickets sold for $70 and children’s tickets for $40. If total sales were $27,750, how much of each ticket was sold?

1 answer

Adult: a
Children: c
a + c = 450
70a + 40c = 27750
Substitute
c = 450 -a

70a + 40(450 - a) = 27750
70a + 18000 -40a = 27750
30a + 18000 = 27750
30a + 18000- 18000= 27750-18000
30a = 9750
30a/30 = 9750/30
a = 325
c = 450 -a
c = 450-325
c = 125