Well, if there are two boys for every three girls then we multiply 30 by 3.
30×5=90.
Next, we divide 90 by 5.
90÷5=18.
Then we subtract 18 from 30.
30-18=12.
That means we have 12 boys and 18 girls.
Finally, we subtract 18 from 12.
18-12=6.
There are 6 more boys than girls.
Have a nice day! :)