Problemwhat is HC meaning? why cannot put 12?

ANSWER
This is Hexadecimal 'C' which is equivalent to Decimal 12. You can write K12 instead of HC.
Reference link: Hexadecimal to Decimal conversion
This is Hexadecimal 'C' which is equivalent to Decimal 12. You can write K12 instead of HC.
Reference link: Hexadecimal to Decimal conversion