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
18 and 35 have no common factors, Therefore, 18 and 35 are coprime numbers. As they have no common factors, 15 and 37 are co-prime numbers. As they have a common factor 5, hence, 30 and 415 are not co-prime. As they have no common factors, 17 and 168 are coprime numbers.
