Answer :
When we try to find the greatest common divisor (HCF) of these three numbers, we find that the only factor they all share is 1. Therefore, the HCF is 1.
When we say that the greatest common divisor (HCF) of three numbers is 1, it means that the three numbers do not have any common factors other than 1.
Let's look at each of the numbers:
- 77 = 7 * 11
- 91 = 7 * 13
- 143 = 11 * 13
We see that the prime factors of each number are different. There are no common prime factors among them apart from 1.
So, when we try to find the greatest common divisor (HCF) of these three numbers, we find that the only factor they all share is 1. Therefore, the HCF is 1.
This implies that 77, 91, and 143 are pairwise coprime, meaning that no pair of them share any common factors apart from 1. And since all three numbers together also have no common factors apart from 1, their HCF is indeed 1.
