The answer is C
We know that men , women and children cannot be fractions the numbers should be integers
We are given the ration of W:C = 5:2
Statement I : C:M = 5:11 , but we only know the ratios not the actual values so insufficient
Statement II : no of women <30 , but where are the men ????
not sufficient
take I and II , we know the following
W:C =5:2 , C:M = 5:11 and W<30 what can we say
We know that W<30 and W:C =5:2 so W can take 5,10,15,20,25 if W can take the above values C can take 2,4,6,8,10 , when W takes these values the only value which satisfies C:M = 5:11 is C= 10
So M = 22
hence we get the answer