no
Yes.
54 and 99 are not prime numbers because they have more than two factors.
I'm uncertain about what you mean by "relatively", but 75 and 99 are not prime. Factors of 75: 1, 3, 5, 15, 25 and 75 Factors of 99: 1, 9, 11 and 99
If the two numbers are relatively prime, their least common multiple is their product. The prime factors of 99 are 3, 3, and 11. Since the two numbers are relatively prime, the possibilities are 9 and 11 or 1 and 99. The pair of 9 and 11 add up to 20 and their least common multiple is 99. So, 9 and 11 are the two numbers.
no
The GCF is 33, which means they are not relatively prime.
No, they are both divisible by 3.
No, 54 and 165 are not relatively prime.
Yes, they are relatively prime.
yes, they are relatively prime.
No, 144 and 165 are not relatively prime. For them to be relatively prime, the number 1 could be their only common factor, but they also have 3 as a common factor.
no 99 is divisible by 1 and 9
Yes.
1, 3, 9, 11, 33, 99 3 and 11 are prime. 1, 3, 5, 11, 15, 33, 55, 165 3, 5 and 11 are prime.
3 x 3 x 11 = 99 3 x 5 x 11 = 165
Since 167 is a prime, any number smaller that 167 will be relatively prime. So, the largest number less than 100, that is 99, is relatively prime.