Aptitude - Numbers - Discussion

Discussion Forum : Numbers - General Questions (Q.No. 1)
1.
Which one of the following is not a prime number?
31
61
71
91
Answer: Option
Explanation:
91 is divisible by 7. So, it is not a prime number.
Discussion:
108 comments Page 5 of 11.

Kaviya said:   1 decade ago
Which number is only divisible by 1 and the same number is called prime number.

Dhruba said:   9 years ago
Sorry, I can't understand. Can anyone explain the answer with an easy method?

Jitu said:   4 years ago
Why only 91 is not a prime number?

In this case, 71 is also divisible by 3.
(13)

Humaun said:   8 years ago
2,5,8- 39 means 23, 29, 53,59,83,89
3-17
6-17
9-7 more easy to memorizing.

Shilpa said:   10 years ago
1!+2!+.....50!/5!

= (1!+2!+......+50!) /1!+2!+.....+5!

= 6!+7!+....+50!

Kimaya said:   1 decade ago
The simple way is we should know tables to find which is a prime number.

Chandan said:   8 years ago
Identify Prime Number.

11 * 1 = 11.
ODD .N
12=2*6, 3*4, 6*2, 12*1 etc.

Shailesh said:   9 years ago
If the number is divisible by 2 and 3 both, then it is divisible by 6.

Karthick said:   1 decade ago
Thank you santhose:) your idea is too good to identify the prime no.

Priyanka.c(IT) said:   1 decade ago
Prime number is defined as divisible by "itself" and by "one" only.


Post your comments here:

Your comments will be displayed after verification.