They have “factors”. Example 2: 5 cannot be divided evenly (except by 1 and 5), so is not a composite number (it is a so called prime number). For example, the composite number 299 can be written as 13 × 23, and the composite number 360 can be written as 2 3 × 3 2 × 5; furthermore, this representation is unique up to the order of the factors. Factors are the numbers that divide into it. 3/3 = 1. In the same way, 2, 5, 7, 11, 13, 17 are prime numbers. The number 11 is also a prime number because it only has two factors: 1 and 11 Example 3 Identify prime and composite numbers from the following list: 73, 65, 172, and 111 Solution Number 73 is a prime number. Yes because 7x6x5x4x3x2x1+5 = 5(7x6x4x3x2x1+1) = 5(1008+1) = 5(1009) Since it has more than 1 factor that is 5 and 1009 So it is a composite number A whole number that can be divided evenly by numbers other than 1 or itself. So, given number is the composite number because it is the product of more than one prime numbers. Example 1: 6 can be divided evenly by 2, so 6 is a composite number. 1-- 1 is only divisible by 1. Find whether the numbers 5 and 6 are Prime or Composite Number? Every composite number can be written as the product of two or more (not necessarily distinct) primes. 1 is itself. The number 1 is neither prime nor composite. It does not have two factors. The best way to figure out if it’s a composite number is to perform the divisibility test. Composite Numbers. If the number is even, then start with the number 2. 5 (1 x 7 x 13 +1) 5 (91 +1) 5 (92) 5 (2 2 × 23). The last digit is not 0 or 5, and it is not a multiple of 7. 1 has only one factor. Other than number 1 every other positive number that is not a prime is a composite number. 3 is a prime number because 3 can be divided by only two number’s i.e. A composite number has more than two factors. Composite numbers are whole numbers that can be divided by numbers other than itself and 1. For example, 2 and 5 are factors of 10. Solution : To find the primality of 5 and 6, first we need to find the factors of the numbers 5 = 1x5 6 = 1x6, 2x3 , 3x2 5 has only 1 and 5 as its factors. In other words a composite number is a positive integer that can be formed by multiplying together two smaller positive integers. If the number ends with a 0 or 5, try dividing by 5. So it is not prime, technically, because it only has 1 as a factor. 5 × 2 × 2 × 23. Definitions. When a number can be divided up exactly it is a Composite Number; When a number cannot be divided up exactly it is a Prime Number; So 6 is Composite, but 7 is Prime. A composite number n is a positive integer n>1 which is not prime (i.e., it can be divided by whole number other than 1 and itself). In problem 2 above, the number 8 has four factors. To do this, you should check to see if the number can be divided by these common factors: 2, 3, 5, 7, 11, and 13. 3/1 = 3. 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