Question

State true or false.

If two numbers are co-primes, at least one of them must be prime.

• A. True
• B. False

Answer 1

The correct option is B False

Numbers with common factor $1$ are co-primes and number with two factors is a prime number.

$9$ and $10$ are co-prime numbers

Factors of $9$ are $1,39$

Factors of $10$ are $1,2,5,10$

But, neither $9$ and $10$ are prime numbers

$\therefore$ the statement is false.