What is the HCF of two consecutive

(a) Numbers? (b) Even numbers? (c) Odd numbers?

(i) 1 e.g., HCF of 2 and 3 is 1.

(ii) 2 e.g., HCF of 2 and 4 is 2.

(iii) 1 e.g., HCF of 3 and 5 is 1.