5, 7 and 17 are prime.
5, 11 and 17 are prime number but 9 and 27 are composite numbers
2, 3, 5, 7, 9 * * * * * 9 is not a prime. The fifth prime is 11.
2, 5 and 7
5, 13 and 17 are prime.
The first 8 prime numbers are: 2 3 5 7 11 13 17 and 19 The median is: (7+11)/2 = 9
5 and 7 are prime numbers. and 3 goes into 9, so the only number that goes into 5, 7, and 9 is 1. They are what we call "relatively prime", even though 9 is not prime, because they have no common factors other than 1.
They are 7 and 17 because they have only two factors
5 yes 7 yes 9 no = 3 x 3
As 315 is ending with a 5 it can be divided by 5 315/5=63 As 6+3=9 then it can be divided by 9 63/9=7 7 is a prime number Then 315 = 32 x 5 x 7
All numbers not divisible by 3 or 9 are relatively prime to 9. This would include 1, 2, 4, 5, 7, 8, 10, 11, 13, 14, 16, 17, etc.
There are 9 prime numbers from 1 to 25:2, 3, 5, 7, 11, 13, 17, 19 and 23
There are 9 prime numbers from 0 to 27:2, 3, 5, 7, 11, 13, 17, 19 and 23