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Pragys app now live for $\text{GATE CSE 2021},$ for set$1$ and set$2$.

Everyone can check the marks and ranks here:

Your Score and where your stand with others:

This time two sessions held, so normalization can play a crucial role.

Explanation of the Contents of Pragys App Video Link:


posted Feb 19 in From GO Admins
edited 3 days ago by


@fahad1247 free marks will not benefit anyone, the ranks will not change, but maybe it'll affect normalization (possibly in a negative way for set 1) as average marks will increase by 2.

@zxy123 can gate score increase ??
Marks to all will definitely affect those students whose marks has been counted for ranking purpose but those not attempted will be benefited
Free marks does increase some peoples' marks. I for one got wrong with TCP, GA and some questions which cost me a whopping 6 mark along with negative marks. Dare I say there're similar questions like that, which costed some people. I'm just 55 now, it could boost or at least level the playing field for some who didn't get that right in GO's predictor.

As for normalization, it's too hard at least for me to guess what would happen.
Same for me msq costed a lot of marks
Is marking of question correct ( I have doubt to one question )?
@Arjun Sir, official answer keys have been released. Could you kindly update the same on Pragys App ?
It is updated except for the relational algebra question. Anyway this is not the final key :)
In set 2- for erroe question- semantic error is given in answer

And for endian question also A;D is given in official keys..

I am going to lose marks for both questions :(
This general aptitude one has made my marks reduced, some one will challenge that one or not

 bro will u challenge the syntax semantic one ?

I am set one guy

The general aptitude Q9 follows the interpretation that either-or === inclusive or, not exclusive or. There are exercise problems in Rosen where in Rosen solution manual they have taken inclusive or interpretation, so inclusive or is expected. If you want to say exclusive or, you have to specify it as "Either I or II but not both".

Is there any way to get marks in this question please give me proper soln I will challenge this soln
So the  general aptitude question must be challenged(of  set 1)
Anyone planning to challenge the GA-9 question and hamming code question of set 1?
One question I will, take care of hamming code. But please give solid soln .
answer key and question paper is out
Please check Electronics and communication GA-6. It is the same question with different wordings and the answer is given as C(either or). Can anyone confirm if this is of similar type or not?
I think set-2 semantic analyzer question needs to be challenged
I think there wasn't a problem with solution to the hamming code per se but, the question in itself had error in it.
Nah, it is different. GATE is treating either or as exclusive-or. In that electronics and communication question either or when interpreted as exclusive or is correct indeed. But in CS set 1 it is not right to interpret it as exclusive-or. It might be debatable that either-or is exclusive or inclusive or, but there is no doubt that neither nor is A nor B. i.e., None of them should be true. And clearly, there doesn't exist even a single case where none of them are true. So although we may argue that whether either or was correct or not, but that doesn't makes neither nor correct. It just can't be right. As @pritishc said even in rosen they have mentioned very often explicitly either or but not both to indicate exclusive or.
@zxy123 would be happy with GA-9's solution at least for now.... lol dude


Let's see what GO discussion leads to

According to Applied too , the answer is Semantic .

  • Conclusion I: Some pathogens are bacteria.
  • Conclusion II: All pathogens are not bacteria.
  • What I feel is both conclusions are the same as All pathogens not bacteria means there are some pathogens that are bacteria
All pathogen aren't bacteria includes the case of having no single pathogen as bacteria which contradicts conclusion 1.
I know bro I am happy but I am trying to be humble because this might be challenged and who knows...
It will most likely be challenged. A lot of people are pissed at losing marks on this. We have to wait till 4th for the final answer key.
The best case will be if both c & d are awarded marks, too much ambiguity in this question
What if someone challenged Final answer key??
You can't challenge final answer key. By definition only the challenges in challenge time period are entertained.
But It will be unfair to those students who marked the answer as given in official key , as they cannot put their views.
That's just life my friend.
No, the challenge period just started... Students are entitled to challenge the answers within the stipulated time, no challenge would be permitted after they'd publish the official key which is by 4th March I believe so.
So no worries...
Please give me soln I will challenge GA Wala set 1 question 9 please take care of hamming code
yes in SET 2

Due to little endian question i am also loosing marks..

Some one need to challenge it!!!
anyone challenging that set 1 GA 9th ques??
I will challenge please give me valid soln[email protected]
@aman let me ask arjun sir

@arjun sir you said 99% chance ans must be C can you provide a valid solution for the GA aptitude 9th question so that we can challenge it.
@Verma Ashish, Both the questions i.e., syntax analyzer and the little-endian question should be challenged.
@ashutosh Yaa please ask Arjun sir with soln I will challenge, please challenge hamming code one also,the print was wrong ,kya pata ga wala change hoke c na hojaye fir kya hoga , I means most of the people will be saying because of us their answer was changed
What about DBMS question?
Set 1 woh toh mera wrong hai
@padamprakash, Can you tell which DMBS question you are talking about?
In set 1 , ans in official key 820 , in GO it is 205
Unpopular Question: Anyone wants to challenge TCP question regarding keep alive timer, specifically option A?

For the GA-9 of set 1 here is a stack exchange link which says that the statement is ambiguous I think it can be used for challenging the question

@Kanwae Kan Any reference for that?
Nahi bhai 820 aayega uska answer it was probability one i.e (10/15+1/20-(10*1)/(15*20))*1200=820

As someone pointed out they have almost same kind of question in Electronics and Communication Engineering. 

Here they have used exact same wordings and everything is same. And so if you go on to interpret it as a ex-or than either or is correct. Also as a matter of fact you dont have neither nor in option otherwise All those in favour of neither nor would have marked that option only by the reasoning that they are giving. But clearly thats not how gate is interpreting it. And since it is now a question of treating either or as exclusive/inclusive or, so if you treat either or exclusive or then I accept that option C is wrong. But still that wouldn't make option D right. Because you will be saying that, None of them are true, which is not the case clearly. Again, if you want to argue that conclusion is valid only if it follows in all cases and all those things than enlighten me how in the world this question another GATE question is correct.


-> For those saying 'Syntax' , See example no 4 :

@PandurangeVitthal you're absolutely right

We should get marks for this 100%
no black is purple is not equivalent to all blacks are not purple
@fahad I know brother. And that is exactly why either or is correct answer here. Because in no case they both will be true together as opposed to our case. I totally agree on that. But still even with that reasoning, neither nor is not correct.

For now, there is no point in arguing in ourselves, I believe everyone who had marked either or should be challenging this question, Don't expect it from others. We can use this question as a reference and rosen too, because there they have been very careful. Even with either or, they explicitly mention "but not both", So if either or unambiguously states that it is exor, why would such an author mention "but not both" several times.

So lets hope for the best and challenge this question. I mean even those who have marked neither nor should go on to challenge this question πŸ˜…. Just kidding.
@vitthal you have a valid sol for GA 9th ques please provide with some reference, i want to challenge this question.
Oh yes sure. Not just me everyone who have whatever references in our favour should provide references. I will collect them and put them under the question's discussion. Don't worry. And everyone else too please share if you get anything relevant.
@PandurangaVitthal Sure just keep updating this thread if you find anything.
And what about hamming code??
Hamming code question also should be challenged surely.
Set 1 people please provide any references for GA Q9

Hamming code and GA Q9 both should be rewarded
for all those in confusion about GA-9,

in EC set ans is definitely either-or

And there's no confusion between the interpretation of either or


issue is with the interpretation of conclusion II in both those problems.

for EC set both conclusions are definitely exclusive and exhaustive, both of them are compliment of each other,


But for GA-9 in set 1, they are interpreting the conclusion II as

"not all pathogens are bacteria" means "there exist at least one pathogen where it's not bacteria"

(but I believe logically it should be same as given in EC set)

This is the actual confusion,apparently everybody here is diverting from actual reasoning they are using..
Forget about actual reasoning ,the question is killing us how, 2.67 marks changing rank drastically it is now becoming the concern of various students
@Aman Juyal

correct reasoning is required to challenge this problem, you won't get anything out of challenging it with an incorrect reasoning,  1 challenge with accurate reasoning is enough to change ans in your favor, than thousands of incorrect reasoned challenges..  So it is most imp here to understand what they are thinking and why they gave neither as ans, then only you can convince them with you answer.


and ik how ranks are affected by it, I'm also getting -2.66 because of this..  :/
Yep, got your point. @Nikhil. And that's quite a valid argument. Indeed, conclusion II should be considered as EC set only.
@Nikhil_dhama @PandurangaVitthal Are you going to challenge?
is the marking scheme(1 or 2 marks quest) correct in GO rank predictor as per the official key?
I just Saw someone getting 90+ marks in Set1 , this has pushed the Average of set1 up.

I won't be surprised if some more such Hidden toppers use the Rank Predictors after Final Key is Released.
@Amcodes that error is with respect to java. In c, the error generated in unknown type name "Integer". Semantic phase does type checking and type coercion only if that type is a part of the programming language.

If the type is not recognized in the first place, i think its an error generated by syntax x phase as it evaluates "Integer x" as "expression expression" which is invalid.
The revised answer keys might have pushed someone from 85-90 to 90-95 range
@123sid does the rank predictor automatically recalculates everyone's marks according to the updated key or it only updates if someone checks with their response sheet again?

Also ME seems to be not interested in it's rank predictor, it's still the same πŸ˜‚

I think it updates once the person checks with his response key again. There is a discussion on fb about this

@nikhil answer will be challenged with proper justification , question is just Bypassing logic ,in gate aptitude is nothing but engineering aptitude so I think it would definitely change . And hamming code question we have to ,I left this question only because of error it was not tough but ambiguity in representation leave me unsolved . And -.67 was also reason not to attempt it . Most of them was like me I guess not attempting that question because of error
@Amcodes @123sid, I had submitted my response sheet instantly on GO at that time only around 100 number of people had submitted, articulation point, TCP and router related question of 2 marks and hamming distance of 1 marks were wrong on GO initially so that's why my marks increased gradually upto 87, now the answer for tuple related question i had 820 and the grammar one of apti I had selected neither nor and both of them turn in my favour so that's why it got jumped
That's Amazing Man, Congrats on being the Topper.
guys, if anyone is challenging set 1 GA question please inform here, -2.67 marks is making a huge difference in the ranks,we should at least give a try with some proper reasoning.
@ashutosh it is difficult to revert back the soln proposed by setter,we all can hope for the best .
@sherrinford03 i need a justification that says there is an ambiguity, the link you pasted they are saying D as correct.

@aman i know that but that ECE ques they gave either as ans, i know it was a bit different, it depends on the interpretation

guys like us will argue that C is correct, others who gave D as ans will argue that ans will be D.

what about the hamming code ques:

in this question d4 bit is given two times and because of that i was not able to attempt this question.

Due to misprint in the question marks should be awarded to all.
@aman its not about reverting back, it is giving marks to both C and D option as @arjun sir said
But in ece statement has atomic interpretation i.e no a is b where as for us it is given a is not b which mean neither a a nor b which was last option . But I thought that neither a nor b or some ---> tautology hence answer would be either or but see what happens
@ashutosh both statement are negation of each other, and in this state it cannot be that both thing will happened only one answer is what for this soln C and D cannot be treated as answer, it cannot be possible I guess only 1 will be the soln may be I would be wrong but this only is my interpretation for this question
No , In case of ambiguity both solutions will be correct .

But again it depends on what they consider . Lets see
By seeing the ece solution it is sure that d cannot be the ans (as in case they are considering each statement for all cases but in ece solution that is not the case they are considering two different scenarios). it must be corrected otherwise it will be very unfair to the students who didn't marked d , -2.67 is a huge marks which create a difference of 200 ranks so this is not acceptable.
@deba1998 what did you mark?
I  mark c that is either or
@debba1998 please challenge this question with a valid argument bro -2.67 is killing me from inside.

@musa yes you are right that is why i am asking again and again did someone challenege.

can you believe my rank was 180-250 before that and now is 325-600
Did any of the guys challenged it or are we waiting for each other....

We can't read mind of question setter there so in my opinion answers should be either or as it is more intuitive and it was question asked in aptitude not in DM
Once a proper reason can be formed as to why the question is ambiguous only then would Gate authorities bother to change the answer. So i guess we'll have to do that first.
challenging starts from 2nd march  probably
@musa exactly!!!

how can we read the mind of the question setter.

@arjun sir please please help us to challnege this ques.

also the hamming code ques
in set 1 bool and int question I think it should be both bool and int, there also I  loose precious 2 marks

@Ashutosh777 and English language is a human language people can interpret same statement in different ways it not like logic which everyone interprets as same...

Question is ambiguous s at worst and "either or " is right answer at best


@deba1998 lets form a group and discuss and then we can challenge it together.

please give your mail id or something.
Make a whatsapp group my no. is 8825063816
@deba1998 ohh GOD,

one apti ques and now that semantic ques also.

i feel for you brother,cause after loosing -2.67 i can feel your pain
Yes bro after releasing of the ans key(keeping the ece solution in mind ) I tried each and every possible cases for that question and conclude that d cannot be the ans in anyway (if we consider both conclusion or single conclusion at a time) how can the officials give d as ans. It is very much depressing
@deba1998 please share your mail or contact, need to plan to challenge this ques
whatsapp - 9748126819

For challenging the answer key we made a group where discussion is going on