Answer: He purchased 15 adult tickets and 35 child tickets.
Explanation:
a = adult tickets
c = child tickets
a + c = 50
15a + 10c = 575
The first equation can be rearranged and substituted into the second equation.
a = 50 - c
15(50 - c) + 10c = 575
750 - 15c + 10c = 575
750 - 5c = 575
-5c = -175
c = 35
The value of c can be substituted into either one of the original equations to find a.
a + c = 50
a + 35 = 50
a = 15
Check:
a + c = 50
15 + 35 = 50
50 = 50
15a + 10c = 575
15*15 + 10*35 = 575
225 + 350 = 575
575 = 575
