Post Gate Experience Journey to IIT Madras

In my last blog I gave very brief description about my journey to different IIT's. In this blog I am going to tell you some of the questions which were asked in for IIT Madras MS 3 year programme.
Also, I will give some suggestions to this year students. Please feel free to ask for any suggestion.

NOTE: This post is for CSE students. Other can ask for suggestions

In 2012 IIT Madras called upto 1000 Gate rank. It is a very good opportunity for high rankers, please do prepare for this exam if you got more than 400 rank. Here, I will post some of the questions, which will give rough idea  and you can prepare accordingly.


There were 2 exams with no gap in between. Part A was 30 min test and Part B was 75 min test.

Description of  Part-A:

This was an easy part. Following are some of the questions:

1-mark: 

1. Number of NAND gates required for XOR
2. Output of C Program 

   main()
   {
   int c;
   printf("%d",scanf("%d",c));
   }
   

3-marks:

1. Bus and auto question. To find when auto will reach..
2. Ram and Shyam age question.
3. Mango Question was like: If someone buys 1 mango then each mango cost is Rs. 50, if some one buys 10 mango then cost of each Mango is Rs. 5, if some one buys 100 Mango then price of each mango is 0.5 and the process continues. We were asked to find "How many we can buy in Rs. 50?" and "How many we can buy in Rs. 40?"
4. 1 permutation question 

Description of Part-B:

This was tough part and was subjective. Out of 9 questions you have to attempt for 5 questions. Following are some of the questions(Note all questions may not be correct as I have written on memory basis)

1. i) Prove or dis-approve for a,b,c,d,e distinct natural numbers
   1/a + 1/b + 1/c + 1/d + 1/e =7/3
   ii) a,b,c,d are distinct natural numbers. (d-a),(b-c) are +ve numbers and (c-d),(a-c) are -ve numbers. Is it possible , give reasons
2. Let a,b,c,d are 4 consecutive numbers of Fibonacci series. Prove or dis-approve ad-bc= ±1
3. There are 6 persons. Prove that there are 3 persons who know each other and other 3 don't know.
4. Solve Recurrence Relation:
   T(n) = T(nb/a) + T((n-b)c/a) +n
   
5. To find total access time
   L1 Cache hit Ratio 0.98 and access time 3 micro-sec
   L2 Cahce hit Ratio 0.92 and access time 20 micro-sec
   Main memory: 1000 micro sec
   
6. Let a ∈(0,1,X). From this set-A and set-B are formed. A compatible set is a set in which either both contains 0 or 1 or X combination with 0 or 1. Find, if the above relation is equivalence or not
7. Program Counter etc with some definition. Write assembly code for auto-increment and auto-decrement opcodes.
8.  An array contain numbers from 1 to n and is of size n. Find, if the array has any element that got repeated. Write code for it.(Hint: You can modify the array) 
9. You have mod-8 counter of frequency 500Hz . Change it to mod-3 counter of 250 Hz

If you crack written test, then there are 70-80% chances that interview will be cleared.

NOTE: If you are not able to clear this exam, then don't get disappointed. You can also try for this in the winter session.(you get 2 chances a year for this)

Interview Experience:

IIT Madras interview consisted of 5-6 professors in a room. Don't get panic. Here each professor is expert  in his own subject or area. They will ask your favorite subject and the professor of only that subject will be interested to ask questions. 

Firstly they will ask why are you opting for MS and they will try to find if you have any re-search interest. If your rank is below 300, then they may doubt that if you will join or not (Sometimes, students below 300 rank prefer for M.Tech)

Secondly they will give you a list of subjects and you can choose one of the subject.

I had chosen Data structures. Then they asked, my preferred topic in Data Structures. 

My Question: Why quick sort  is preferred over heap sort, even though quick sort worst case complexity is O(n^2) while for heap sort it is O(nlogn) for all cases.

They were trying to find my approach of solving the ans.  I was unable to answer this question properly, though they selected me. 

I am not posting the answer of interview question. If you don't get answer then feel free to ask.

There are 40 students who finally got selected out of 60 students who got shortlisted after written. There were around 300 students who appeared for written.

Please feel free to ask for suggestion. I will reply back your queries.