Question

In a school out of 300 students, 70% are girls and 30% are boys. If 30 girls leave and no new boy is admitted, what is the new percentage of girls in the school?

Answer 1

total number of children in a school = 300

No. of. boys = 30% of 300

`= 30/100 xx 300 = 90`

and no.of.girls = 70% of 300

`= 70/100 xx 300 = 210`

Now no.of girls left = 30

∴ No. of. girls after leaving 30 girls

= 210 - 30 = 180

and No. of. children in the school = 180 +  90 = 270

∴ % of girls now `=180/270 xx 100 = 200/3%`

`= 66 2/3%`