Question 21285
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?