Question

Which of the following is a pair of co-primes?  

(i) (32,62)

(ii) (18,25)

(iii) (31, 93)

Answer 1

(i) (32, 62)

Given numbers are 32 and 62

For pairs to be co-primes there should be no common factor except 1

Factorization of 32 and 62 are

Here, we can see that 2 is the common factor. So, (32,62) is not co-prime.

(ii) (18, 25)

Given numbers are 18 and 25

For pairs to be co-primes there should be no common factor except 1

Factorization of 18 and 25 are

Therefore, there is no common factor. So, (18,25) is co-prime.

(iii) (31, 93)

Given numbers are 31 and 93

For pairs to be co-primes there should be no common factor except 1

Factorization of 31 and 93 are

Here, we can see that 31 is the common factor. So, (31, 93) is not co-prime.