Aptitude - Numbers - Discussion
Discussion Forum : Numbers - General Questions (Q.No. 1)
1.
Which one of the following is not a prime number?
Answer: Option
Explanation:
91 is divisible by 7. So, it is not a prime number.
Discussion:
108 comments Page 4 of 11.
Santosh said:
1 decade ago
Hiii friends .......just apply this formula to find the not prime no or prime no...
n*n>=p
1)here P is the given no
2)find the squares which is > or = to the given no P
3)find the prime nos < or = n
4)check weather the given P no is divisible by prime nos which is < or =n
5)if divisible ....it mean it have more than two factors so given P is not a prime no.
6)if not divisible it mean the given no P is prime no
n*n>=p
1)here P is the given no
2)find the squares which is > or = to the given no P
3)find the prime nos < or = n
4)check weather the given P no is divisible by prime nos which is < or =n
5)if divisible ....it mean it have more than two factors so given P is not a prime no.
6)if not divisible it mean the given no P is prime no
Hariharan said:
1 decade ago
Hi, santhosh.
Please explain your formula with an example.
Please explain your formula with an example.
Raji said:
1 decade ago
Hi, i would like to share with a example
to find 31 prime or not
by the above formula it can be written as 6*6>=31(p)
now upto 6 the prime nos are 2,3,5,7
31 is not divisble by any of these no,
hence it would be a prime no
to find 31 prime or not
by the above formula it can be written as 6*6>=31(p)
now upto 6 the prime nos are 2,3,5,7
31 is not divisble by any of these no,
hence it would be a prime no
Vengala rao said:
1 decade ago
Hai, santhosh your explanation is very nice.
Santhosh said:
1 decade ago
How you will consider 7 when you are checking for 31?
Karthick said:
1 decade ago
Thank you santhose:) your idea is too good to identify the prime no.
Yogendra said:
1 decade ago
Thanks santosh very much
Manali said:
1 decade ago
Thank you santosh.
R.DEIVASIGAMANI said:
1 decade ago
How to identify prime number and not prime number by easy method?
Santosh(pydah) said:
1 decade ago
91 is divided by 7 thats why it is not prime number.
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