Which of the following is a pair of co-prime numbers?​

(A) 14, 15

(B) 18, 27

(C) 17, 68

(D) 63, 81

Which of the following numbers are co-prime?

(a) 18 and 35 (b) 15 and 37 (c) 30 and 415

(d) 17 and 68 (e) 216 and 215 (f) 81 and 16

Question 5 (d)

Which of the following numbers are co-prime:
17 and 68