Let the number of boys in the group be x.Number of girls in the group = 0.7x.x+0.7x=85⇒x=50Number of boys playing badminton = 60% of 50 = 30.Number of boys playing onlybadminton = 50% of 50 = 25.Number of children playing onlytable tennis = 40% of 85 = 34.Number of children playing bothbadminton and table tennis = 12.Number of children playing only badminton=85−(34+12)=39.Number of girls playing onlybadminton =39−25=14.