Which of the following is a pair of co–primes?
Choose the correct choice:
A) (16, 62)  B) (18, 25)  C) (21, 35)  D) (23, 92)  E) none
Solution   H.C.F. of 18 and 25 is 1. So, they are co-primes.   Answer (18, 25)
<result>B</result>
Which of the following is a pair of co–primes?