Let x =the total number of children
2/5 of = 240
2/5*x=240
2x=1200
X=600
X=600-240= 360
X=360+240=600
The total number of children in the school is 600.
Hoped that helped. Sorry if it's confusing, my teacher taught this to us really strangely. I tried to simplify it.
So the total number of boys is 360. So all you have to do is add 360+240 to get 600.
