The only reason somebody should be flopping around with such a softball question is if they for some reason think that they're being asked to find a near-optimal way of computing square roots. The only reason the candidate would be allowed to get stuck in a dead end for a long period of time is if the interviewer doesn't know what he's doing. But I see absolutely nothing wrong with asking questions of this general type.
And again, I do not think this is a good interview question. I just think it's bad for a different reason than the original poster claimed. Which was that it's supposedly not solvable even by top engineers unless they've recently implemented the algorithm.
And again, I do not think this is a good interview question. I just think it's bad for a different reason than the original poster claimed. Which was that it's supposedly not solvable even by top engineers unless they've recently implemented the algorithm.