Two–thirds of the children in the fourth–grade class are girls. If there are 12 girls, what is the total number of children in the class?

Question

Two–thirds of the children in the fourth–grade class are girls. If there are 12 girls, what is the total number of children in the class?

Answer 1

Let x be the total number of children in the class.

 

Two–thirds of the children in the fourth–grade class are girls, and there are 12 girls so that

(2/3)x = 12

x = 12/(2/3)

   = 12(3/2)

   = 18.

 

The total number of children in the class is 18.