

Companies using tests aimed at separating stars from duds - cwan
http://www.boston.com/business/articles/2010/09/12/when_hiring_employers_use_tests_to_separate_stars_from_duds/

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wtracy
Hmm, the balls puzzle has me stumped.

Say I pull one ball from each box, and I get two white balls and a black ball.
Obviously the box that the black ball came from the box that contains all
black balls.

But how can I tell which box contains all white balls, and which contains a
mix of black and white balls, without pulling out a second ball?

~~~
Dove
You've missed a key piece of information: _The labels are all wrong._ Not just
unreliable. _Wrong._

(P.S. You can do it in one ball.)

~~~
oconnore
These puzzles are more about recognizing fuzzy areas in the problem definition
than about any sort of logic. In conversational English, "the labels are all
wrong" does not guarantee that each label is guaranteed wrong, only that at
least one of the labels is done incorrectly.

Another example: You have a room with one light bulb. Outside the room are
three switches. How do you determine which switch controls the light bulb by
only opening the door once.

This problem requires you to suspend certain assumptions about the real world
(you can't see light coming from underneath the door), while preserving other
ones (you can hold the light bulb, and it heats up, it stays hot). Solving the
problem is more about finding the right level of fuzzying the problem
definition than any sort of test of logic.

