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ENEMY AND THE PRIME NUMBERS



   Let us assume that you and your enemy belongs to the same town.(hope you do not have an enemy. Even if you have one, make sure he does not know about prime numbers).  Both of you have left the town for greener pastures and you both visit the home town periodically.  You do not want to meet or face your foe even accidentally.  How to choose the timings cleverly?  This is just an example with a smile to understand the nature of prime numbers.  

      Suppose you choose to visit the town at every 17th day (prime number).  And your 'friend' select to visit every 10th day.  The visits will not mostly coincide because 10 is not the factor of 17.  For that matter, 17  is not divisible by any other whole number. Suppose you unwisely choose every 2nd day, 5th day,  20th day.  You are more likely to meet your foe face to face sooner or later.  It is because 2, 5, and 20 are mutual factors or mutually divisible with 10 which is chosen by your foe.  

 Example:  Suppose if you select 20th day; your enemy's second visit and your first visit will coincide.  This idea may not be suitable for humans.  But some insects follow the prime number cycle of years to escape from predators.  They appear only in prime number years.  They literally go underground during other years.  

 NOTE ON PRIME NUMBERS
     Prime numbers are divisible by themselves and by one and not by any other whole numbers.  
Some examples:  2, 3, 5, 7, 11, 13, 17, 19, 23, 29.
Till date, there is no formula to find primes.  Only we can test a number for primality.  In the natural number sequence, prime numbers appears randomly and they are unpredictable.      

Comments

  1. How do we know18 November 2017 at 22:00

    This is really a great way to teach children about prime numbers!

    ReplyDelete

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