Question

In a class the ratio of boys to the girls 7:8.what part of whole class are girls?

Answer 1

total number of boys and girls in the ratio = 8+7=15
ratio of girls = 8
number of girls = 8/15.
∴(8/15) th part of whole class are girls 

Answer 2

Let the number of girls be x.
girls = 8x
ratio= 7+8
=15
part of girls=8/15