Which of the following numbers are co-prime? (c) 30 and 415
30 and 415 Factors of 30 are 1, 2, 3, 5, 6, 10, 15, 30 Factors of 415 are 1, 5, 83, 415 Common factors = 1, 5 Since, their common factor is other than 1. Hence, the given two numbers are not co-prime
