Question

At a family reunion were the following people: one grandfather, one grandmother, two fathers, two mothers, four children, three grandchildren, one brother, two sisters, two sons, two daughters, one father-in-law, one mother-in-law, and one daughter-in-law. But not as many people attended as it sounds. How many person were there ?

• A. 5
• B. 10
• C. 15
• D. 7

Answer 1

The Correct Option is D

The problem here is to determine the number of unique individuals at a family reunion considering overlapping roles. We can do this by identifying the potential roles each person fulfills and combining them logically. Let's break down the roles based on the relationships provided:

• Grandfather: Also a father and possibly a father-in-law.
• Grandmother: Also a mother and possibly a mother-in-law.
• Two fathers: One is the grandfather; the second father is likely one of the children of the grandparents and also a son.
• Two mothers: One is the grandmother; the second mother could be the daughter-in-law and also a daughter.
• Four children: Could be the combination of the second father (as a child of the grandparents), the second mother (as a daughter to the grandparents), and possibly two others from the grandchildren.
• Three grandchildren: Children of the second parents group (the second father and mother).
• One brother: Could be the second father.
• Two sisters: Could include the second mother and another child from the grandparents.
• Two sons: One is the second father and another could be among the grandchildren.
• Two daughters: One is the second mother and another could be among the grandchildren.
• One father-in-law: The grandfather.
• One mother-in-law: The grandmother.
• One daughter-in-law: The second mother (wife of the second father).

By consolidating these relationships and roles, we conclude that there are 7 distinct people at the reunion: the grandfather, the grandmother, their son (also a father), son-in-law's wife (also a mother and a daughter-in-law), and their three grandchildren. Thus, the answer is:

7