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:
116 comments Page 6 of 12.
Chandan said:
9 years ago
Identify Prime Number.
11 * 1 = 11.
ODD .N
12=2*6, 3*4, 6*2, 12*1 etc.
11 * 1 = 11.
ODD .N
12=2*6, 3*4, 6*2, 12*1 etc.
Deepak kumar said:
9 years ago
This is the easiest way to check prime number.
Ex that 31, So put the nearest square of this number 25<31>36, so square of 31 is something 5. Something, then find the number below 5 prime number i.e. 2 and 3, now check 31 is divisible by this number or not if this is divisible then it is not the prime number, if this is not divisible then it is a prime number.
Ex that 31, So put the nearest square of this number 25<31>36, so square of 31 is something 5. Something, then find the number below 5 prime number i.e. 2 and 3, now check 31 is divisible by this number or not if this is divisible then it is not the prime number, if this is not divisible then it is a prime number.
Humaun said:
10 years ago
2,5,8- 39 means 23, 29, 53,59,83,89
3-17
6-17
9-7 more easy to memorizing.
3-17
6-17
9-7 more easy to memorizing.
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:
1 decade 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:
1 decade ago
Please give brief explanation of prime numbers.
Revanna p said:
1 decade ago
How does 91 come?
J.KRISHNAVENI said:
1 decade 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.
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