A family consists of grandparents, parents and three grandchildren. The average 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 average age of the family ?  Choose the correct answer:  A) 31( 5/7)  B) 31( 5/9)  C) 31( 5/2)  D) 31( 4/7)  E) 41( 5/7)
Required average = (67 * 2 + 35 * 2 + 6 * 3) / (2 + 2 + 3)   = (134 + 70 + 18) / 7 = 222 / 7   = 31(5/7) years.   31( 5/7)nswer: 31( 5/7)
<result>A</result>
A family consists of grandparents, parents and three grandchildren. The average 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 average age of the family ?