Question

There are 600 students in the third grade, of which there are twice as many girls as boys. How many boys and girls are there in the third grade?

Answer 1

Suppose there are $x$ boys in the third grade. Then there are $2x$ girls in the third grade.

There are 600 students

$$x+2x=600$$

$$3x=600$$

$$x=\dfrac{600}{3}$$

$$x=200$$

$$2(200)=400$$

There are 200 boys and 400 girls in the third grade.