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:
113 comments Page 6 of 12.
Deepika said:
10 years ago
@Nidhin.
Thank you for this shortcut. It's really helpful.
Will you tell me the shortcut to remember prime number above 100?
Thank you for this shortcut. It's really helpful.
Will you tell me the shortcut to remember prime number above 100?
Pooja.r.m said:
10 years ago
Thank you @Nidhin. Now I understand it easily.
Nagasai said:
10 years ago
If the number is 91 when we divide by 2 it is equal to 45.5 numbers in between 45.5 to 91 cannot exactly divide 91 except itself so when we take below that numbers 45.5. It is easy to tell given is prime or not.
NIDHIN M Z said:
10 years ago
2, 3, 5, 7.
1--1379.
2--39.
3--17.
4--137.
5--39.
6--17.
7--139.
8--39.
9--7.
These are the shortcuts for the prime number.
Lets see, 1--1379 means 11 is prime, 13 is prime, 17 is prime, 19 is prime.
Likewise 2--39 means 23 is prime, 29 is prime. This is the easy way to memorize the prime number. Its very easy (just you have to memorize the above given no).
1--1379.
2--39.
3--17.
4--137.
5--39.
6--17.
7--139.
8--39.
9--7.
These are the shortcuts for the prime number.
Lets see, 1--1379 means 11 is prime, 13 is prime, 17 is prime, 19 is prime.
Likewise 2--39 means 23 is prime, 29 is prime. This is the easy way to memorize the prime number. Its very easy (just you have to memorize the above given no).
Shivani said:
10 years ago
Please give brief explanation of prime numbers.
Revanna p said:
10 years ago
How does 91 come?
J.KRISHNAVENI said:
10 years ago
@Dilipkumar.
Only for few numbers given for short cut in prime numbers. So please given for other numbers in the short cut method.
Only for few numbers given for short cut in prime numbers. So please given for other numbers in the short cut method.
Shailesh said:
1 decade ago
If the number is divisible by 2 and 3 both, then it is divisible by 6.
Akshay said:
1 decade ago
Please, someone, know the method for divisibility of 6?
Shamanth said:
1 decade ago
How can we find the number of prime numbers below 'n' numbers ?
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