Prime number is a one which is not divisible by any other number expect one.
Given a number, to find whether it is prime or not,the process of checking whether it is divisble by any other number is time consuming and tedious. There is a simple alternative solution for this. All prime numbers satisfy the following condition.
If n is prime,
(n-1)! is congruent to (n-1)mod n.
Let us take an example. Take n=7.
(n-1)!=6!=720.
720 is congruent to 6 mod 7.
Therefore, 7 is a prime number.
putta
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1 comment:
Putta! Budding Einstein! Nee solradhukku munnadi naanae soltaen! Poadhuma? ;)
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