Two grandparents, two parents, and three grandchildren make up a family. The average present age of the grandparents is 67 years, that of the parents is 35 years and that of the grandchildren is 6 years.What is the present average age of the family (in years)?

$31\frac{5}{7}$

ATQ,

Sum of present age of grandparents = 134

Sum of present age of parents = 70

Sum of present age of grand children = 18

Average age of family = \(\frac{134 + 70 + 18}{7}\)

                                  = \(\frac{222}{7}\)

                                  = 31\(\frac{5}{7}\)