Question

Tell whether the number is prime or composite.

18

Short answer

18 is a composite number.

Step-by-step solution

Step-1-Recall the concept of prime and composite numbers

Prime numbers are the numbers which are divisible by 1 and itself.

Composite numbers are the numbers which have factors other than 1 and itself.

Step-2- Find the factors of the given number

Observe that 18 is divisible by 1, 3, 6, 9 and 18.

Therefore, the factors of 10 are 1, 3, 6, 9 and 18.

Step-3- Conclusion

Since 18 has factors other than 1 and itself, it is a composite number.