An octal number system uses the digits from

1. 0 to 8
2. 1 to 8
3. 0 to 7
4. All of them

The base of a hexa-decimal number is represented by

1. H16
2. 16
3. 15
4. None

To express a hexa-decimal number to its binary equivalent, each hexa-decimal digit is expressed as

1. 2 bits form
2. 3 bits form
3. 4 bits form
4. None

The binary equivalent of a hexa-decimal digit 12(C) is represented by

1. 1010
2. 1011
3. 1101
4. 1100