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?
If the gathering included one brother, does that mean
exactly one brother? If so, I have a bit of a problem with the "four children, three grand children" part, as every human being alive today (barring laboratory experiments) is both a child and a grandchild.