Using Hamming code , we can correct the errors .. For that we need to add some bits in between the bits of the message at specified locations , which are known as padding bits . These bits are placed at places which are powers of 2..i.e. at position number 1 , 2 , 4 etc starting from left i.e. from MSB (most significant bit)..
Now to know how many padding bits needed we have the following equation :
2r >= m + r + 1
The simple reason behind this equation is that we have to keep rth padding bit which is the last padding bit at 2r position..
Hence here message size given = 12 B = 96 bits
Hence m = 96 bits
Thus we have :
2r >= 96 + r + 1
==> 2r >= 97 + r
==> rmin = 7
Hence number of padding bits = 7