__ ____Is 15 is a composite number or not ?__

__Is 15 is a composite number or not ?__

- As we already know that, the number having factors 1 and the number itself is the prime number.
- And numbers having more than these two factors are the composite numbers.
- To check whether the number 15 is composite or not first we have to find its factors.

Contents

**Factors of 15:**

- If we have taken numbers from 1, 2, 3…for checking factors of 15, we found that 15 has factors 1, 3, 5 and 15. Hence, we must say that 15 is a composite number.
- Thus, 15 is the composite number.
- If we multiply 15 by 1, 2, 3, then we get the multiples of 15 which are 15, 30, 45…and so on.

__About the number 15:__

__About the number 15:__

- 15 has more than two factors which are 1, 3, 5 and 15 and hence it is the composite number.
- 15 is the odd composite number and it is not the perfect square also.
- If we divide 15 by 1, 3, 5 and 15 then we get remainder as zero. Hence, 1, 3, 5 and 15 are the factors of 15.

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__Note:__

__Note:__

- 15 is not the perfect square.
- Factors of 15: 1, 3, 5, 15
- Prime factors of 15: 3 and 5

**Conclusion:**

- 15 is the composite number which has factors 1, 3, 5 and 15.
- And hence, 15 is not the prime number.

**Multiple Choice Questions:**

**1) 15 is a**

a) odd number

b) Prime number

c) Composite number

d) Both a and c

**Ans: d) both a and c**

**2) The prime factors of a composite number 15 are**

a) 1

b) 3 and 5

c) Both a and b

d) 151

**Ans: b)3and 5**

**3) 1 is the not prime factor of 15 because**

a) It is the prime number

b) 1 is neither prime nor composite number

c) Both a and b

d) Given statement is false

**Ans: b) 1 is neither prime nor composite number**