Which pair of numbers is relatively prime?
a. 26 and 99
b. 90 and 117
c. 100 and 202
d. 201 and 444

A. 26 and 99 is the correct answer.

26= 2*13
99= 3^(2)*11
GCF (26,99)= 1
Because GCF (26,99)= 1, 26 and 99 are relatively prime.

Hope this would help~

Answer=A

Two numbers are relatively prime if they have no common factors (aside from 1). So lets solve for the factors of the number to see if they are relatively prime...

A. Relatively Prime 
26=1,2,13,26
99=1,3,9,11,33,99

B. NOT RELATIVELY PRIME
90=1,2,3,5,6,9,10,15,18,30,45,90
117=1,3,9,13,39,117

C. NOT RELATIVELY PRIME
100=1,2,4,5,10,20,25,50,100
202=1,2,101,202

D. NOT RELATIVELY PRIME
201=1,3,67,201
444=1,2,3,4,6,12,37,74,111,148,222,444

4(2+3c)=56
8+12c=56
-8        -8
12c=48
/12    /12
c=4