SOLUTION: Three out of 5 people attending Dustin's party were girls. If 12 girls attended, how many people were at the party?

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Question 21285: Three out of 5 people attending Dustin's party were girls. If 12 girls attended, how many people were at the party?
Answer by wuwei96815(245) About Me  (Show Source):
You can put this solution on YOUR website!
Well, we don't know how many people attended so let's call that number x the unknown.

Now, we have to write an equation with x in it so that we can solve the equation and find out what x is.

3 out of 5 people attending or 3/5 of x were 12 girls.
Another way of saying the same thing is 3/5 x = 12.
Let's solve 3/5x=12.
Multiply both sides of the equation by 5/3 in order to isolate x.
5/3 times 3/5x = 5/3 times 12.
We get: x = 20.

Did you understand all of that?