Write any two pairs of co-primes, where none of the two is prime.
Co-primes are those numbers which do not have any common factor (or whose HCF is 1)
one pair can be 4and9
second pair can be 9and16 (where 4,9and16 are composite numbers)
What is the HCF of any two co-primes?
Write 5 pairs of co-primes?