Which of the following pairs is NOT coprime?

Correct option is D

Given:

Four pairs of numbers:

A. (11, 13)

B. (15, 17)

C. (17, 23)

D. (17, 34)

We need to determine which pair is NOT coprime.

Formula Used:

Two numbers are coprime if their greatest common divisor (GCD) is 1.

Solution:

Option A: (11, 13)

GCD(11, 13) = 1 (since both are prime numbers).

=> Coprime.

Option B: (15, 17)

GCD(15, 17) = 1 (no common factors other than 1).

=> Coprime.

Option C: (17, 23)

GCD(17, 23) = 1 (since both are prime numbers).

=> Coprime.

Option D: (17, 34)

GCD(17, 34) = 17 (since 34 is a multiple of 17).

=> Not coprime.

The pair (17, 34) is NOT coprime.