Besides not being related to day to day job a lot of these questions also select for a specific set of knowledge. If you've done that particular class of proble

Besides not being related to day to day job a lot of these questions also select for a specific set of knowledge. If you've done that particular class of problems (graph, tree, dynamic programming etc), then you do well, if not then you don't. They also typically have a single or very limited number of solutions, so if you deviate early the chances of recovering is very low. I see this style of interview questions pretty frequently and I really question their effectiveness, vs say something more open ended and fluid.