"Instructor: Oh right...................................what's the square root of 423?"
Yeah, right. ROTFLMAO
Aside from spare capacity, they may want to see where you place your priorities.
Sure is a sorry way to weed people out though, as many really want that job and are nervous for the interview and trying hard to do good in a new sim and then you throw them out like this.
I'm now sorry to hear that this has happened to not only a FO but also a DEC.
Everyone be forewarned.