Question

what will be the ratio of the boys to girls:if total students of class is (65),boys=30

Answer 1

Here is your answer
Boys = 30
Girl = 65 - 30 = 35

Ratio of boys to Girl =30 : 35
=6 : 7

Hope it helps you

Answer 2

no. of boys = 30
total students of class = 65
no. of girls = total students of class - no. of boys
=65-30
=35
now...boys:girls = 30:35=6:7