Sean Lange (7/24/2013)
I would have to say that is an absolutely horrid interview question. It is not testing your skills with sql server. I have seen the binary AND around the forums but I have never come across it in the real world (at least not in sql server).
It's called "Bitwise AND" :
http://msdn.microsoft.com/en-us/library/ms174965.aspx
I have used it few times...
I'll try to find one thread on this forum where I've used it to help to achieve quite interesting requirements.