Binary Codes

Question

Que.

Represent the decimal number 6,248 in (a) BCD, (b) excess‐3 code, (c) 2421 code, and

(d) a 6311 code.

Ans. a)0110 0010 0100 1000

       b)1001 0101 0111 1011

      c)0110 0010 0100 1110 but it might also be 1100 1000 0100 1110 Is it Possible how would we assign the number to 2421 Please Explain???

    d)1000 0011 0110 1011

Is the answer Correct for a,b,c,d???

Answer 1

$a)$ Correct

$b)$ Correct

$c)$ The $2421$ code is the Aiken code. It has a standard coding system where first $5$ numbers (0,1,2,3,4) start with binary $0$ and the remaining (5,6,7,8,9) start with binary $1$. 

https://en.wikipedia.org/wiki/Aiken_code

"One might think that double codes are possible for a number, for example 1011 and 0101 could represent 5. However, here one makes sure that the digits 0 to 4 are mirror image complementary to the numbers 5 to 9."

So the correct representation for $6248$ in 2421 code is $1100$ $0010$ $0100$ $1110$.

$d)$ Not sure. Here also, ambiguity is there for coding 4 and 7, as $4$ can be represented as both 0101 and 0110 and $7$ as 1001 and 1010 in $6311$ code. But I couldn't find any standards for that.

Comments

Ok right then 4 and 5 also can be represented in two ways. So what does that table mean, is it just an example?

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It should be mirror image of the complement since the weights add to 9. No matter you start with zero or one. Anyways the table shown has first five digits starting with 0 and next 5 with 1. Is it not a standard code., please clarify.

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yes, it is not standard that first five digits starts with 0 and next 5 digits starts with 1.... In the table they given just an example