Check whether two prime numbers are always co-primes?

 

Check whether one prime and one composite number are always co-primes?

Check whether two composite numbers are always co-primes?

Express the given number as a sum of two or more primes?

$13$

Express the given number as a sum of two or more primes?

$130$

Express the given number as a sum of two or more primes?

$180$

Express the given number as the sum of two odd primes:

$36$

Express the given number as the sum of two odd primes:

$42$

Express the given number as the sum of two odd primes:

$84$