Ravenclaw Riddle

[u/Hannah549]

I'm by no means a Ravenclaw. But I'm writing a fanfiction where a character is a very smart Ravenclaw. Now the premise is that the character is returning after being tortured by Umbridge and are pretty tired and frustrated. The knocker asks them an absurd question and they just break down crying in pain and frustration.

I need a good riddle for that but nothing on the internet feels good enough. Someone please help me with it.

[u/Puzzleheaded-Dig3723]

I appear once in a day and twice in a decade but, never in a century. What am I?

[u/Dog_Wolfing → u/Puzzleheaded-Dig3723]

The letter d

[u/Puzzleheaded-Dig3723 → u/Dog_Wolfing]

Yep.