Some people would call it an "enigma" or a "conundrum."
A hink-pink.
You simply call it "no solution".
You just write, "No Solution."
A set would not normally have a solution. An equation or an inequality might.
Yes, it can be. For example, "He was seeking an answer for the riddle" (to the riddle).
The German.
A sun block, I'm not sure a pure guess
The riddle is that there is no riddle. Buddha teaches that the only thing that limits our ability to see is the ignorance that we have self created and what happens to us is a result of how we think, what say and what do.
unriddlerriddle solver
What do you call Edward from Warsaw? Polish Ed.
riddle
T. E. Riddle has written: 'The vision and the call' -- subject(s): Biography, Mystics
I'm sorry but is this a riddle? How am I supposed to know?
tom riddle
A hink-pink.
backwards! (elddir) LOL
SireWorked on my riddle box!