Of the 65 families in a locality, 45 have children and 10 have retired individuals as members. Of the families, 8 have both children and retired individuals as members. How many of the families have neither children nor retired individuals as members?

Correct Answer: 18
Number of families having children or retired individuals or both = 45 + 10 - 8 = 47 So, number of families having neither children nor retired individuals = 65 - 47 =  18.