Fill in the blanks:The smallest odd composite number is ____

Question

Vedantu Content Team · Accepted Answer

Hint: We solve this problem by using the definition of composite number.A number having more than 2 factors is called a composite number.We have that the number having only 2 factors is called the prime number.We consider the odd numbers starting from 1 and check whether the number has more than 2 factors or not.Complete answer:We are asked to find the smallest odd composite number.We know that a number having more than 2 factors is called a composite number.Let us consider the first odd number that is 1Here, we can see that the number 1 has one and only one factor that is 1We know that the number having only 2 factors is called the prime number.So, we can conclude that 1 is neither prime nor composite.Now, let us consider the next odd number that is 3We know that the factors of 3 are 1 and 3 onlyBy using the prime number definition we can conclude that 3 is the prime number.Now, let us consider the next odd number that is 5We know that the factors of 5 are 1 and 5 onlyBy using the prime number definition we can conclude that 5 is the prime number.Now, let us consider the next odd number that is 7We know that the factors of 7 are 1 and 7 onlyBy using the prime number definition we can conclude that 7 is the prime number.Now, let us consider the next odd number that is 9Now, let us use the prime factorisation method for 9 then we get$$\Rightarrow 9={{3}^{2}}$$Here, we can see that the number 9 have three factors as 1, 3 and 9We know that a number having more than 2 factors is called a composite number.Therefore we can conclude that the number 9 is a composite number.Here, we can see that we checked the odd numbers from smallestSo, we can say that the first odd composite number will be the smallest odd composite number Therefore, we can conclude that the smallest odd composite number is 9Note: We need to note that the number 1 is neither prime nor composite.If a number has exactly 2 factors then it is a prime number and if a number has more than 2 factors then it is a composite number.But here the number 1 has only 1 factor. So, it is neither prime nor composite.