How you convert the 53.2 octal number into binary number?

Answer 1

To covert octal to binary, write down a 3-bit equivalent for each digit. In this case it would be 101 011 . 010, or 101011.01

An excellent answer above. But if you want a lazy way to do it, you can also use the standard 'calculator' provided with Windows, click on 'View' then 'Scientific'. The radio buttons let you select Decimal, Hex, Octal or Binary.