At Nelia’s family reunion, 4 out of every 5 people are 18 years of age or older. Half of the remaining people are under 12 years old. If 20 children are under 12 years old, how many people are at the reunion?

Respuesta :

since we do not know how many adults are, set up the equation like this:

4/5=20/x

then, you would cross multiply and get

4x=100

Divide four on both sides, and you have

x=25