Practice Prime Numbers

Introduction – Practice prime numbers:

A prime number is a natural number. This has exactly divisible by one and itself only. If any one number divisible by more than these two factors that is not a prime number. First twenty-five prime numbers are listed below up to 100.

First twenty-prime numbers 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, and 97.The only one even prime number is 2. Because other than 2 all even numbers will divisible by two. 

Finding Prime Numbers – Practice Prime Numbers:

Finding prime number less than two digits are very easy. If it is three digits we have to follow some rules.

For example:
Determine the number 281 is prime number or not?
Step 1:

Find the square root for the given number. That is 281 = 16.76
Then we have to round- up the decimal value16.76 as 17.
Step 2:

Mention all the prime number up to 17. That is 2, 3, 5, 7, 11, 13 and 17.
Step 3:
Now divide the given number by all obtained prime numbers. The number is not divisible by any number. So the given number is a prime number.

Example Problems – Practice Prime Numbers:

Problem 1:

Determine the number 150 to 155 is prime number or not?

Solution:

150 – Factors for 150 are 1, 2, 3, 5, 6, 10, 15, 25, 30, 50, 75 and 150. So 150 is not a prime number.

151 – Factors for 151 are 1 and 151 only. So 151 is a prime number.

152 – Factors for 152 are 1, 2, 4, 8, 19, 38, 76 and 152. So 152 is not a prime number.

153 – Factors for 153 are 1, 3, 9, 17, 51 and 153. So 153 is not a prime number.

154 – Factors for 154 are 1, 2, 7, 11, 14, 22, 77 and 154. So 154 is not a prime number.

155 – Factors for 155 are 1, 5, 31 and 155. So 155 is not a prime number. I like to share this prime factorization of 72 with you all through my article.

Problem 2:

Determine the number 307 is prime number or not?

Solution:

The given number 307 has two factors only. Those factors 307 are 1 and 307 only. So the given number 307 is considered as a prime number.           

Problem 3:

Determine the number 330 is prime number or not?

Solution:

The number 330 has more than two factors. Those factors are 1, 2, 3, 5, 6, 10, 11, 15, 22, 30, 33, 55, 66, 110, 165 and 330. Hence the given number 330 is not a prime number.

Practice problems – practice prime numbers:

Problem 1:

Determine the number 593 is prime number or not?

Solution:

The given number 593 is a prime number.

Problem 2

Determine the number 641 is prime number or not?

Solution:

The given number 641 is a prime number.

Problem 3

Determine the number 432 is prime number or not?

Solution:

The given number 432 not a prime number.