Aptitude - Numbers - Discussion
Discussion Forum : Numbers - General Questions (Q.No. 12)
12.
The sum of first five prime numbers is:
Answer: Option
Explanation:
Required sum = (2 + 3 + 5 + 7 + 11) = 28.
Note: 1 is not a prime number.
Definition: A prime number (or a prime) is a natural number that has exactly two distinct natural number divisors: 1 and itself.
Discussion:
29 comments Page 1 of 3.
Murali said:
1 decade ago
To find a prime number:
the numbers 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97 etc
This total 25 no.s is not divisible by ant other no.
for example:
1. 11 is not divisble my any other no.
2. 17 is not divisble my any other no.
3. 71 is not divisble my any other no. etc etc etc
if the number is not divisible ny any other no. then we called as prime number
the numbers 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97 etc
This total 25 no.s is not divisible by ant other no.
for example:
1. 11 is not divisble my any other no.
2. 17 is not divisble my any other no.
3. 71 is not divisble my any other no. etc etc etc
if the number is not divisible ny any other no. then we called as prime number
Sundar said:
1 decade ago
@Ansar
1 is not a prime number.
A prime number (or a prime) is a natural number that has exactly two distinct natural number divisors: 1 and itself.
The smallest twenty-five prime numbers (all the prime numbers under 100) are:
2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97.
Hope this will help you. Have a nice day!
1 is not a prime number.
A prime number (or a prime) is a natural number that has exactly two distinct natural number divisors: 1 and itself.
The smallest twenty-five prime numbers (all the prime numbers under 100) are:
2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97.
Hope this will help you. Have a nice day!
Megnah said:
7 years ago
@All.
I have one simplest method to find the sum of first n natural no's by using the formula n(n+1)/2.
For eg:
To find the sum of first 50 natural no's,
(NOTE:always natural no starts with 1),
Where n=50.
Then 50(50+1)/2 =>50(51)/2 =>2550/2.
=>1275.
Ans: The sum of the first 50 number is 1275.
I have one simplest method to find the sum of first n natural no's by using the formula n(n+1)/2.
For eg:
To find the sum of first 50 natural no's,
(NOTE:always natural no starts with 1),
Where n=50.
Then 50(50+1)/2 =>50(51)/2 =>2550/2.
=>1275.
Ans: The sum of the first 50 number is 1275.
(1)
Greeshmitha pillalamarri said:
8 years ago
The first five prime numbers are 2, 3, 5, 7, 11 and we know that prime numbers start from 2. Now, the sum of first five prime numbers is 2+3+5+7+11=28 so it is clear that sum of first five prime numbers are 28. Thank you!
(1)
Sajjad said:
4 years ago
2+3+5+7+11=28,
1 is not a prime number because the prime number has only 2 different factors, 1 has only one factor therefore it is not a prime number.
1 is not a prime number because the prime number has only 2 different factors, 1 has only one factor therefore it is not a prime number.
(1)
Kowsalya said:
1 decade ago
To find a prime number :
The number must divide itself only, For example 2,3,5 these numbers only divide the same tables only.
The number must divide itself only, For example 2,3,5 these numbers only divide the same tables only.
HUZAIFA JALAL said:
1 decade ago
A prime number (or a prime) is a natural number greater than 1 that has no positive divisors other than 1 and itself.
Shashank said:
1 decade ago
The method to find a prime no. is 6n-1 or 6n+1 except 2 & 3. . .1 is neither prime nor composite.
Pranjal Bajpai said:
5 years ago
@Babu.
1 is not prime as we don't have the choice to check it's divisibility other than itself.
1 is not prime as we don't have the choice to check it's divisibility other than itself.
Fairu said:
8 years ago
Please tell me how to find the sum of first 100 prime numbers.
Any formula is there for that?
Any formula is there for that?
(2)
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