
Neal T. answered 10/05/15
Tutor
5.0
(2,169)
Math!
Jenny,
There are several ways to get the answer you're looking for. Here's one approach.
First let's assign variables, c = # of children and a = # of adults.
Now let's look at what we know:
$5 per child to attend the fair
$7 per adult to attend the fair
$3, 379 total collected, so $5c + $7a = $3,379 and
We also know that (c + a) = 587... total of children and adults attended,
Let's stack both equations and solve
5c + 7a = 3,379
c + a = 587
let's multiply the bottom expression by -5, and then add them together:
5c + 7a = 3,379
-5c - 5a = -2,935
-5c - 5a = -2,935
0c + 2a = 444
2a = 144, divide both sides by 2 and a (# of adults) = 122
Now it's easy, because
c + a = 587, and a = 122 so
c + 122 = 587, subtract 122 from both sides to get:
c = 587 - 122 = 465 children
So 122 adults and 465 children attended the fair.
I hope this helps!
Neal