total age of grandparents = 2 × 67 = 134 years total age of parents = 2 × 35 = 70 years total age of 4 childrens = 4 × 6 = 24 years total age of the family = 134 + 70 + 24 = 228 years Number of members in the family = 2 + 2 + 4 = 8 Average age of the family =