Sure, there's a lot of noise in using brainteasers as a predictor of problem-solving ability; but IMO they do offer some predictive value. It's an opportunity for them to see how you think. They're hiring you to solve problems - and the easiest way for them to gauge problem solving ability is to ask you to solve problems.
"Would you want to work with the guy who builds a water-displacement scale/barge, taxis a 747 to the docks, and then weights the jumbo jet using that, instead of simply calling Boeing in the first place?"
Umm, just because you CAN solve these brainteasers doesn't mean you don't know how to call Boeing! Knowing more than one way to solve a problem is almost never a weakness.
And as for the blind bike example, the candidate was not being practical, just being a pain in the &*%. Just answer the question without being a smart alec.
Except brainteasers are vulnerable to prior exposure. Once you've heard enough of them you have a bunch of tools at the ready for any others that use the same kinds of intuitive leaps -- and you may not even need to do that if you get asked ones you already know.
Just pretend you're really trying hard and voila, eventually spout the correct answer you appeared to have thought up on the spot.
I hear these little brain teasers and can't help but think of Monty Python's Holy Grail: "What is the air-speed velocity of an unladen swallow?"
Yeah, I'm the guy who would ask "747-300 or 747-400?".
Granted it could probably be figured out by taking the vector of the thrust to lift ratio of the engines and wings at take off, but something tells me you'd go through a lot of planes that way rather than designing it with that in mind.
"Would you want to work with the guy who builds a water-displacement scale/barge, taxis a 747 to the docks, and then weights the jumbo jet using that, instead of simply calling Boeing in the first place?"
Umm, just because you CAN solve these brainteasers doesn't mean you don't know how to call Boeing! Knowing more than one way to solve a problem is almost never a weakness.
And as for the blind bike example, the candidate was not being practical, just being a pain in the &*%. Just answer the question without being a smart alec.