1st equation: 3a +2c =33.50
2nd equation: 1a + 4c = 30.50
multiply 2nd equation by 3 so the a's equal the first equation
1a +4c = 30.50 x 3 = 3a +12c = 91.50 (3rd equation)
subtract 1st equation from 3rd equation:
3a +12c =91.50 - 3a + 2c = 33.50 = 10c = 58
c=58/10 = 5.80
children's ticket cost 5.80
now substitute that into the 1st equation and solve for a
3a +2c =33.50 =
3a +2(5.80) = 33.50
3a +11.60 =33.50
3a = 21.90
a = 21.90/3 = 7.30
adult tickets cost $7.30