A
29 is prime but 39 is composite
9, 21, and 39 are divisible by three, so they are composite. 3, 17, and 41 have only two factors, 1 and itself, so they are prime.
23 and 27 are prime numbers whereas 36 and 39 are composite numbers.
13 is a prime number and 39 isint a prime number
I suggest factoring each pair of numbers, and checking whether they have, or don't have, common factors. A pair of numbers is said to be "relatively prime" if they have no common factors (their greatest common factor is 1). For larger numbers, Euclid's algorithm could be used, but for such small numbers, factoring is probably faster.
The numbers 23, 29, 31 and 37 are prime.
10 and 21
A
The prime numbers (factors) of 39 are: 3 and 13
No 36 & 39 are not prime.
29 is prime but 39 is composite
9, 21, and 39 are divisible by three, so they are composite. 3, 17, and 41 have only two factors, 1 and itself, so they are prime.
23 and 27 are prime numbers whereas 36 and 39 are composite numbers.
13 is a prime number and 39 isint a prime number
39 is the product when the two prime numbers 3 and 13 are multiplied.
It is 37 which is a prime number because it has only two factors