Photo by gotplaid?.
While checking out the book table after a homeschool group meeting, Maria Jones glanced up to see her children laughing with some kids she did not recognize. Driving home, she asked about the new family, but Alex and Leon had been too busy exchanging silly stories to even ask the strangers’ names.
“Well,” Leon said, “the boy told me he has twice as many sisters as brothers.”
No way!” said Alex. “The girl told me that she has the same number of brothers and sisters.”
How can that be?
Edited to Add
The answer to this puzzle is now posted:
To Be Continued…
Read all the posts from the January/February 1999 issue of my Mathematical Adventures of Alexandria Jones newsletter.
Denise Gaskins' Let's Play Math 
Where’s the answer!?
I will post the answer in another post (hopefully this weekend), along with the answers to the block puzzles. But if I told you the answer too soon, you wouldn’t have the fun of trying to figure it out!
I like this. I could use it as a little throwaway intro to the awful age problems (that I do not teach!)