Let us number of boys=x
and the number of girls= x of 2/5
=2x/5
Now,
According to question,
x/1 + 2x/5 = 35
5x/5 +2x/5 = 35
7x/5 = 35 7x = 35*5 x = 35/7 * 5/7
x = 5*5 x = 25then, the number of boys = 25
and , the number of girls = 2x/5 = 2/5*25/5
=10 ans