Question

2s complement of - 539 is 539 so in her it is 21B should be the answer

Comments

Duplicate of: https://gateoverflow.in/728/gate-cse-2001-question-2-10

Answer 1

The question is not about 2's complement of -539, rather what is the 2's complement representation of -539.

In 2's complement representation negative numbers are represented as 2's complement of its absolute value while positive numbers are representes as they are.

So, $(-539)_{10} = 2's(001000011011)_2 = (110111100101)_2 = (DE5)_{16}$.

For $539$, answer would have been $(001000011011)_2 = (21B)_{16}$

Comments

@arjun Sir ,  I interpreted the question in other way. I understood what you told. but one thing to be clarified..

is 2s complement of -539 is 539 , right ?

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2' s complement of -ve value only we have to calculate from 1s complement

and 2's complement of +ve number is same as its binary representation

rt?

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@Akhil

2's complement of -539 is 539?

I'm not sure. First of all we need to know how to represent negative numbers and then only complement it.

@Srestha yes, in 2's complement representation. You can see Morris Mano or Hamacher for this.

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@arjun sir , iam geting more confused .

So what is the 2s complement of (-539)

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I don't know :) As far as I know 2's complement is defined for unsigned numbers and for negative numbers we assume a given representation. So, if anyone asks 2's complement of (-539) it would be implied that they use 2's complement represenation.

https://en.wikipedia.org/wiki/Two%27s_complement

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@arjun sir,

Any change/update in answer ?

If I follow anser given by you im getting

2's complement of (-539) as 110111100101

But If I follow these answers by Praveen sir

• https://gateoverflow.in/35626/is-2s-complement-of-57-110001110

Im getting  2's compliment of (-539) as 539 .

Which one to follow !  Confused !

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you can read the below comments there..

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pc what i understand like thsi

2's complement of -539 is 539

2's complement representation of -539 is -539

Answer 2

For 2's Complement representation of -539 (emphasize on representation word)

2's complement representation is a weighted Code representation.

To represent negative no. MSB position ( which must 1) weight is -ve rest are +ve so

-539=-1024+485

101 1110 0101

MSB weight -1024 rest made +485 so collectively they are -539

Now to represent in hexa it should be muliple of 4 bit so add extra 1 in MSB(sign extension it wont affect the Value it remain still -539)

So finally

1101 1110 0101

= (DE5)16