(a) First part In Binary coded octal system each octal digit is represented in 3 bit binary. To calculate octal Equivalent of 215, Divide 215 repeatedly and then collect remainder from bottom to top.
i.e.,(215)10=(327)8 Now represent each digit in 3 bit binary, i.e., 011 010 111 and when we store this into 12 bit register. The register content will be 000 011 010 111 . Second part In binary coded decimal system, each digitis represented in 4 bit binary code. Hence, the register will look like 0010 0001 0101.