The Hamming distance between two-bit strings is the number of bits that would have to be flipped to make the strings identical.
To detect $d$ errors we require a minimum Hamming distance of $d + 1$.
Correcting $d$ bit flips requires a minimum Hamming distance of $2\times d + 1,$ where $d$ is number of bit in errors.
For the first blank, each error detection we need $1$ parity bit
For $3$ bit error detection we need $3$ parity bits. So, $3$ parity bits requires here.
Also, we can calculate this way, formula is $d+p+1 \leq 2^p$ where, $d=$ data bits , $p =$ parity bits , $d=4$ bits given.
According to $1^{\text{st}}$ question, $d=4$ so $4+p+1\leq 2^p$
$p+5 \leq 2^p$ now if p$=2$ it becomes $7 \leq 4,$ Not possible.
If $p=3$ it becomes $8\leq 8,$ which is possible.
So, $p$ must be $3.$[ Minimum value of $p$ is $3$ ]
The second blank the $3$-bit error detection is possible because the code has a minimum distance of $\underline{\qquad}$answer is $3+1=4,$ where d$=3.$ Formula used is $d+1.$
The answer for $2$ blanks is $[ 3,4 ].$