MICROSOFT, the world’s biggest software company, has developed its own unique — some would say eccentric — recruiting methods. It receives about 12,000 CVs each month. Without human intervention, each is scanned for key words and logged into a database. Promising résumés lead to a screening interview, usually by phone. Finally, those who pass muster get a “fly-back” — a trip to Microsoft’s headquarters in Redmond, Washington State, for a full-day marathon of famously difficult interviews.

“We look for original, creative thinkers,” says Microsoft’s website. “Our interview process is designed to find those people.”

At some point, a recruiter will lob in a so-called Microsoft question. It may be mathematical, with a “correct” answer, or open-ended. In either case the recruiter is at least as interested in the way you answer the question as in the answer itself.

“Get over your fear of trick questions,” says a company publication. “You will probably be asked one or two. They are not exactly fair, but they are usually asked to see how you handle a difficult situation.”

With the use of puzzles in its hiring decisions, Microsoft plays to the more appealing side of the digital generation mythos — of maverick independence and suspicion of established hierarchies. Puzzles are egalitarian, Microsoft’s people contend. All that matters is your logic, imagination and problem-solving ability.

How are yours? Here is an example, with my pass notes attached. Would Bill Gates employ you? Microsoft’s grading system for each answer is roughly as follows:

0 points — no hire
1 point — no hire
infinity +1 points: fair
infinity squared +1 points — the “right” answer

Q. How many points are there on the globe where, by walking one mile south, one mile east, and one mile north, you reach the place where you started?

Start by drawing a mental map: One mile south, one mile east, and one mile north covers three sides of a square. You ought to end up a mile east of where you started. The situation seems impossible, and you might think the answer is zero points.

Try again. The only way to make sense of the situation is to remember that the compass directions are relative ones applied to the surface of a sphere. At the North Pole, every horizontal direction is south. As long as you start precisely at the North Pole, you can walk a mile in any direction and that will count as walking south. Not only that, but a subsequent one-mile-east leg will curve in a circle centered on the North Pole. At any rate, it will if you interpret the puzzle to mean that you not only point yourself due east but constantly adjust your direction so that your bearing remains due east throughout the second mile. That then allows a final, straight, one-mile-north leg returning to the pole. The journey looks like a wedge of pie rather than an open square.

So the North Pole is one point where this could happen. Notice that it couldn’t happen at the South Pole. At the South Pole, every direction is north. You can’t go a mile south from the South Pole.

You might therefore think the answer is one point, and again you’re wrong. You’re wrong because you can manage such a journey near the South Pole. Imagine starting out from a point a little more than a mile from the South Pole. You travel a mile due south, make a 90-degree turn east, and execute a complete circle about the South Pole of one mile circumference — at every point traveling due east, of course — and then backtrack north a mile to the starting point.

There is not just one point from which you can do this but an infinity of them. You can start from any point that is the correct distance from the South Pole.