A mother and her friend are talking about how many chidren they have. The friend knows how many daughters the mother has, but doesn't know how many sons she has. The mother says:

"All of my children have the same amount of brothers and the same amount of sisters as the other children."

Now the friend knew how many sons she had. How many sons did the mother have?

She has one son, no daughters.

Sons = s
daughters = d

s-1=d
1-1=0

Posted by Lisa on 2003-10-25 14:42:11