A family gathering included 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.

What can be the minimum number of people present in the gathering?

Solution:

There is a couple, a grandfather and a grandmother. This couple has one son. The son is married to a woman, and they have three children (one boy and two girls). Therefore there are two fathers (grandfather and his son), two mothers (grandmother and the son's wife), four children (son and his three children), one brother (the son's boy), two sisters (the son's two girls), and the rest are obvious. The minimum number is 7.

Posted by Ju-Ju on 2003-02-06 17:46:37