Child admission is $5.10 and adult admission is $8.70. Three times as many adult tickets as child tickets were sold, for a total of $1123.20 tickets. How many child tickets were sold?

Answer 1

These used to really confuse me, too. Let's see what we can do!

Let c = the # of children's tix.

Let a = the # of adult tix.

a = 3c (ah, confusing, but think about it!)

5.10c + 8.70a = 1123.20

Now, whatever is on one side of an equal sign can swap for what's on the other, because they are EQUAL.

5.10c + 8.70(3c) = 1123.20

5.10c + 26.10c = 1123.20

31.20c = 1123.20

c = 36 children's tix

a = 3(36)

a = 108 adult tix