Write down separately the prime and composite numbers less than 20.


Prime numbers are the numbers that has only two factors: 1 and number itself.


A composite number has more than two factors.


Prime numbers less than 20 are;


2, 3, 5, 7, 11, 13, 17 and 19.


Composite numbers less than 20 are;


4, 6, 8, 9, 10, 12, 14, 15, 16, and 18.


Note: Every Number that is not a prime number is a composite number.


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