Riddle and the Math Question

It's bedtime.

But Alexander still kept talking.

He threw tons of riddles to Helios. And no matter what the riddle ended, it always began with Helios being trapped in the room. But the riddles did not even have a logic in them that even the Jesus could not know the answer. It felt like you walked in a building, but you can't either find an elevator to go upstairs, or get an exit to step out. However Alexander did not realize he was giving out dead-end riddles. Instead, he was so excited that he could not stop talking.

Alexander said: Dada, now I've got a good riddle.

Helios whined, why should I need to answer riddles all night？What about you tell me what the answer is to 9x6.

Alexander cried out loud: Dada, don't you know the differnce between riddle and math question？We are talking about riddles.

Helios replied: But at least math question has a answer! And your riddles don't!

I laughed like I was crazy. And I added: But Alexander's riddles have their own answers defined by Alexander to his convenience.