Which pair of numbers is relatively prime? a. 119 and 209 b. 88 and 121 c. 144 and 165 d. 42 and 385

119 and 209 is the only pair of relatively prime number.

Step-by-step explanation:

We are given the following information:

Relatively Prime:

a) 119 and 209 - No shared factors. hence, they are co-prime.

b)  88 and 121 - The greatest common divisor is 11 and hence they are not relatively prime.

c) 144 and 165 - The greatest common divisor is 3 and hence they are not relatively prime.

d) 42 and 385 - The greatest common divisor is 7 and hence they are not relatively prime.

you can use a^2+ b^2=c^2