Question

Which of the following prime numbers are co-prime? a. 20 and 25
b. 27 and 29
c. 52 and 117

Answer 1

Given:

$a. \ 20 \ and\ 25\\b. \ 27 \ and\ 29\\c. \ 52 \ and\ 117$

We have to find which of the above prime numbers are co-prime.

As we know that the Co-prime numbers are those numbers if the only positive factor that divides them is 1.

We are solving in the following way:

We have,

$a. \ 20 \ and\ 25\\b. \ 27 \ and\ 29\\c. \ 52 \ and\ 117$

Option A:  $(20,25)$ The factor that divides both of them is$1,4,5$.

Option B: $(27, 29)$ The factors that divide both of them are$1$.

Option C: $(52,117)$ The factors that divide both of them are$1,13$.

In reference to the above definition, we can say that $(27, 29)$are co-prime numbers.

Hence Option b) is correct.