Question

which of the following pair is not coprime which of the following pair is not coprime a 8,10 b 11, 12 c 1,3 B 31,33

Answer 1

I think it's a. 8 , 10 as both the numbers are composite numbers.

Hope this helps

Answer 2

Given:

• Some numbers pair are given

       A. 8,10

       B. 11, 12

       C. 1,3

       D. 31,33

To Find:

• Which of the following pair is not co prime.

Solution:

Two numbers are co prime if their highest common factor (HCF) is 1.

A. 8,10

Here, Factors of 8 = 1, 2, 2, 2

           Factors of 10 = 1, 2, 5

          Common factor = 1, 2

Since , both have more than one common factor, therefore, they are not co-prime numbers.

B. 11, 12

           Factors of 11 = 1, 11

           Factors of 12 = 1, 2, 2, 3

           Common factor = 1

Since , both have only one common factor, i.e., 1, therefore, they are co-prime numbers.

C. 1,3

           Factors of 1 = 1,

           Factors of 3 = 1, 3

          Common factor = 1

Since , both have only one common factor, i.e., 1, therefore, they are co-prime numbers.

D. 31,33

           Factors of 31 = 1,  31

           Factors of 33 = 1, 3, 11

          Common factor = 1

Since , both have only one common factor, i.e., 1, therefore, they are co-prime numbers.

Thus, (8,10) is not not co prime.