Question

How many prime numbers are there from 1 to 10?

Answer 1

Hint: The numbers which are not divisible by any other numbers except 1 and the number itself. So we can tell that a prime number has a total 2 factors, those are 1 and then the number itself. We will check if a number is prime or not by finding the number of factors. The numbers which are not prime are composite numbers except 1 , 1 is a special number.

Complete step by step answer:
The number includes from 1 to 10 are 1, 2, 3,4,5,6,7,8,9 and 10
First we will start with 1 – 1 is not a prime number though it has only one factor. 1 is not a composite number also because it does not have more than 2 factors. 1 is a special number.
2 is a prime number as it has only two factors; 1 and 2.
3 is also a prime number because it has 2 factors; 1 and 3.
4 have more than 2 factors, those are 1, 2, and 4 so it is not a prime number.
5 have only 2 factors 1 and the number itself so it is a prime number.
6 have more than 2 factors; 1, 2,3, and 6 so it is a composite number.
7 is the prime number it has 2 factors only.
8 is not a prime number; it has more than 2 factors; 1, 2 ,4 and 8.
9 is not a prime number it has 3 factors 1, 3 and 9.
10 is a composite number it has 4 factors; 1, 2,5 and 10.
So the prime numbers from 1 to 10 are 2, 3, 5, 7

So there are 4 prime numbers from 1 to 10.

Note: There are infinitely many prime numbers present in the world. 2 is only an even prime number. Another even number has at least one factor that is 2. We can check if a number is prime or not by finding the number of factors from 1 to square root of that number. If the count is greater than 1 it is composite otherwise it is a prime. Always remember 1 is not a prime number.