Exactly one of Al, Ben and Cal is a knight and the remaining two are liars. They are conversing among themselves about Dan who is a common friend of the three of them. They say:
Dan has more than a million dollars.
No, Dan has less than a million dollars.
But, surely Dan has at least a dollar.
Who is the knight? Who are the liars? How much money does Dan actually have?
*** This puzzle has at least two solutions.
If Ben is the knight then DAN has ZERO dollars (1st solution)
If Cal is the knight then DAN has a million dollars
exactly. (2nd solution)
if Al is the knight then CaL is a knight as well -- contradiction ,
THEREFORE THERE ARE ONLY TWO SOLUTIONS
(given 0 dollara means 0 OR LESS)