Perhaps the only goal is to find out whether or not they know about shit-bifting, particularly if they'll be expected to optimize code on any sort of particular hardware.

There's another potential motive, however. And that is whether or not candidates understand how it's possible to model real systems using discreet mathematics -- particularly that subset of discreet mathematics bounded by such things as bit-width.

That Von Neumann was a real stinker.

Cheers,
Matt

P.S. Speaking of discreet systems. Ever tried to figure out whether or not two integral functions intersect or not (or how often)? Euclid had it figured out. It's useful for figuring out potential solutions for diophantine systems of functions.