The correct option is
C 15 : 16
the ratio of the number of men to the number of women at a concert is
53 let the ratio constant is x for this ratio ,then no of men =5x
and the number of women is =3x
the ratio of the number of women to the number of children is =25
let the ratio for this ratio is y
then number of women is =2y
and number of children is = 5y
no. of women = 3x=2y , x=2y3
sum of women and men is = 2y+5x=2y+5×2y3=16y3
then ratio of children to sum of women and men is =5y16y3=1516
hence optionA is correct.