Who is who?

[BMAD]

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 were there, and who were they?

[dark_magician_92]

7??

[bonanova]

I love this puzzle.

First, the terminology used:

Every person is a son or a daughter of their parents.

Assuming there are more than four people in the group, it must then be the case that

"son" means "I am male and at least one of my parents is present," and

"brother" means "I am male and at least one of my siblings is present."

Similar conclusions can be drawn from the other relational statements.

One brother and two sisters then requires siblings numbering 3 (and only 3)

in one (and only one) generation level in the group.

More later. The in-law relationships are going to be (as in real life) the most challenging.

[BMAD]

7??

Correct! Care to explain your answer.

[dark_magician_92]

since there are g.father and g.mother involved, we have 3 generations at least. The mother in law and father in law helps in idenrifying that they have a son who is married to a woman. the two fathers would be the g.father and his son, similar logic for 2 moms. Now there are 3 grandchildren and the 4th child is the son of the g.father and g.mother. There are 2 sisters and 1bro, so the 3 children can be 1 boy, 2 girls and all rest conditions are satisfied by the grp of these 7 ppl

[bonanova]

Can someone draw that family tree?

[BMAD]

Edited May 14, 2013 by BMAD