Prime numbers are whole numbers that have 2 factors: only 1 and itself.
Examples:
· 2 - 1 x 2 (2 factors)
· 3 - 1 x 3 (2 factors)
· 23 - 1 x 23 (2 factors)
On the other hand, composite numbers are whole numbers that consist of more than 2 factors.
Examples:
· 4 - 1 x 4, 2 x 2 (4 factors)
· 6 - 1 x 6, 2 x 3 (4 factors)
· 100 - 1 x 100, 2 x 50, 4 x 25, 5 x 20, 10 x 10 (9 factors)
Question: Is 15 a prime number?
List down all the factors of 15 first so that we'll figure out if it's a prime number.
15 = 1 x 15, 3 x 5 (4 factors)
It has 4 factors. Does it mean that it's a prime number?
NO, because as I've said earlier, prime numbers have only 2 factors but it's stated above that 15 has 4 factors.
15 is a composite number.
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Have a wondrous day =)
