Question

A classroom contains an equal number of boys and girls. if 9 girls​ leave, twice as many boys as girls remain. what was the original number of students​ present

Answer 1

So,

since the amount of boys that remain is twice the amount of girls that left:
Its, 9X2=18
18 boys
(we can assume that the amount of girls that left is equal to the amount that remains)

And since the amount of girls is = to the amount of boys,
its 18+18=36

So the original amount of students present is 36 students

Hope this helps!