Best Interview Question

Question:

Imagine yourself at a certain point on earth.

If you go 100 km South, followed by 100 km East, followed by 100 km North, you end up at your starting point.

What is that point and how many such points are possible?

Don’t go over directly to the solution, think about it!

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Need help?

Hint: Take the 100 as X in the question. If you replace 100 by X in the answer as well, it still stands true.

What I mean to say is that the answer is generic for any value of X.

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Still can’t?

• Most people would come up with this solution which is pretty obvious but a little ambiguous.
  
  The North Pole

But what does it mean to go South when you’re standing at the North pole?
Every direction points toward South from the North pole. So we cannot resort to this answer without ambiguity.

• Some people would think about the possibilities of this one.
  
  The South Pole
  But now what does it mean to go South from the South pole?
  It makes no sense. So this one’s ruled out.
• The neat answer is:
  
  Any point 100 km North to the latitude whose circumference is 100 km.
  Refer the image.

Explanation: In the part where you go 100 km East, you reach the same point where you started going East from as you complete a full circle on that latitude.

Therefore, there are infinite such points for which this is possible.

Hope you found this fun to think about.