3. HCF of co-prime numbers 4 and 15 was found as follows by factorisation : 4 = 2 × 2 and 15 = 3 × 5 since there is no common prime factor, so HCF of 4 and 15 is 0. Is the answer correct? If not, what is the correct HCF?
No, the answer is not correct. 1 is the correct HCF.
As
4 = 2 2 1
15 = 3 5 1
1 is common in both so HCF is 1.