Parity

Parity Why $H(A)=H(C)$ where $C$ is $A$ with an additional parity bit?
Why $H(A)=H(C)$ where $C$ is $A$ with an additional parity bit?
What is the purpose of adding parity bit?Why would you expect a CRC to detect more errors than a parity bit?Where is the parity bit added?How to add ...