| Aspect | The 2003 CAT Leak | The 2004 CAT Retest |
|---|---|---|
| The Event | A massive paper leak by a syndicate led by Ranjit 'Don' Singh. | The first-ever cancellation and retest in CAT history. |
| The Impact | 1.27 lakh students' futures thrown into chaos. Trust in the system shattered. | IIMs created the toughest CAT paper ever, with extreme security. |
| The Response | National outrage, CBI investigation, and arrests. | An LRDI set that mirrored the exact mechanics of the paper leak. |
| The Legend | The scandal that forced IIMs to change everything. | The birth of the 'Mastermind' question, a legendary act of academic roasting. |
Future IIMer, some stories are more than just history. They are lessons. The CAT 2004 'Mastermind' question is one such lesson, straight from the IIMs themselves. It's not just an LRDI set; it's a statement about integrity, pressure, and razor-sharp logic. Let's break it down.
The story behind the ultimate comeback
Picture this: November 2003. The CAT exam is leaked by a man named Ranjit Singh, infamously known as Ranjit Don. Chaos erupts. The dreams of over 1.2 lakh students are put on hold. For the first time ever, the IIMs cancel the exam.
The retest was scheduled for February 15, 2004. The IIM faculty, feeling the weight of the nation's trust, took extreme measures. They personally guarded the question papers overnight in a Pune warehouse. They were determined to create a paper so secure and so tough that it would restore faith in the system.
And they delivered. The CAT 2004 paper became legendary for its difficulty. But the real masterstroke was a specific LRDI set. The question setters designed a puzzle that was a direct commentary on the leak itself, modelling the exact way a 'mastermind' would distribute answer keys to a network of cheats. It was a message. It was academic revenge.
The infamous 'mastermind' LRDI set
Here is the exact question that appeared in the CAT 2004 paper. Read the setup carefully. Every word matters.
Directions for questions 133 to 137: Answer the questions on the basis of the following information.
Recently, the answers of a test held nationwide were leaked to a group of unscrupulous people. The investigative agency has arrested the mastermind and nine other people A, B, C, D, E, F, G, H and I in this matter. Interrogating them, the following facts have been obtained regarding their operation. Initially the mastermind obtains the correct answer-key. All the others create their answer-key in the following manner. They obtain the answer-key from one or two people who already possess the same. These people are called his/her sources. If the person has two sources, then he/she compares the answer-keys obtained from both sources. If the key to a question from both sources is identical, it is copied, otherwise it is left blank. If the person has only one source, he/she copies the source answers into his/her copy. Finally, each person compulsorily replaces one of the answers (not a blank one) with a wrong answer in his/her answer key.
The paper contained 200 questions; so the investigative agency has ruled out the possibility of two or more of them introducing wrong answers to the same question. The investigative agency has a copy of the correct answer key and has tabulated the following data. These data represent question numbers:
| Name | Wrong Answer(s) | Blank Answer(s) |
|---|---|---|
| A | 46 | — |
| B | 96 | 46, 90, 25 |
| C | 27, 56 | 17, 46, 90 |
| D | 17 | — |
| E | 46, 90 | — |
| F | 14, 46 | 92, 90 |
| G | 25 | — |
| H | 46, 92 | — |
| I | 27 | 17, 46, 90 |
Q.133: Which one among the following must have two sources? (1) A (2) B (3) C (4) D Answer: (3) C
Q.134: How many people (excluding the mastermind) needed to make answer-keys before C could make his answer-key? (1) 2 (2) 3 (3) 4 (4) 5 Answer: (2) 3 people
Q.135: Both G and H were sources to: (1) F (2) B (3) I (4) None of the nine Answer: (4) None of the nine
Q.136: Which of the following statements is true? (1) C introduced the wrong answer to question 27 (2) E introduced the wrong answer to question 46 (3) F introduced the wrong answer to question 14 (4) H introduced the wrong answer to question 46 Answer: (3) F introduced the wrong answer to question 14
Q.137: Which of the following two groups of people had identical sources? (Group I: A, D and G) (Group II: E and H) (1) Only I (2) Only II (3) Neither I nor II (4) Both I and II Answer: (4) Both I and II
How to crack the mastermind's network
This set looks intimidating, but it hinges on one core principle. The rules clearly state how blanks are created: only when a person compares keys from two different sources and finds a mismatch.
The Golden Rule:
- No Blanks = 1 Source. The person copied directly from one source.
- Has Blanks = 2 Sources. The blanks represent the questions where their two sources disagreed.
Let's apply this. Single-Source People (No Blanks): A, D, E, G, H. Two-Source People (Have Blanks): B, C, F, I.
The Mastermind (M) has the perfect key. The first level of people must have received it from M. Since they have only one source (M), they will have no blanks. These are A, D, and G. They each introduce one wrong answer.
- A got the key from M, introduced the error at Q46.
- D got the key from M, introduced the error at Q17.
- G got thekey from M, introduced the error at Q25.
Now look at the other single-source people: E and H. They have no blanks, so they each have one source. But who?
- E has wrong answers at 46 and 90. E couldn't have gotten the key from M, who is perfect. E must have sourced it from someone who already made a mistake. Looking at our list, A has a mistake at Q46. So, E's source is A. E copied A's key (with the Q46 error) and then introduced a new error at Q90.
- H has wrong answers at 46 and 92. Same logic. H's source must be A. H copied A's key and introduced a new error at Q92.
Finally, let's look at a two-source person, like B.
- B has blanks at 46, 90, and 25. This means B's two sources had different answers for these questions. Let's find two people whose combined errors match B's blanks. E has errors at (46, 90). G has an error at (25). The Mastermind's key is correct for all three. When B compares E's key and G's key, they will mismatch at Q46, Q90, and Q25, creating the blanks. So, B's sources are E and G. B then introduced a new error at Q96.
You can apply this same deductive logic to figure out the sources for C, F, and I to solve the entire set. This isn't about maths; it's about pure, structured thinking. This is what IIMs, including IIM Indore for its IPM program, test for.
Why this 20-year-old question matters in 2026
With recent controversies around exams like NEET-UG, the principles of fairness, integrity, and merit are more important than ever. This CAT 2004 question is a timeless reminder that IIMs value these principles above all else. They don't just want students who can solve formulas; they want future managers who can think critically under pressure and navigate complex, ambiguous situations with a clear head.
Such was the heartbreak that they even included a question on the Mastermind and the process it followed to make the leak undiscoverable. Academic roasting literally means this. , Shekhar Dutt, Sleepy Classes
For an IPMAT aspirant, this question teaches you to read the rules carefully, establish a core logical framework, and build your solution step-by-step. The skills needed to solve this network puzzle are the same skills you'll need in an IIM classroom and a corporate boardroom. It's about deconstructing a problem, identifying the key constraints, and tracing the flow of information to find the solution. Master this, and you're not just preparing for an exam; you're preparing to be a leader.
FAQs
What is the CAT 2004 'Mastermind' question?+
It's a legendary Logical Reasoning & Data Interpretation (LRDI) set from the CAT 2004 retest. It was created after the 2003 paper was leaked, and the question's logic mimicked the exact process of how an answer key is leaked through a network, making it a famous case of 'academic roasting'.
Why is the CAT 2004 paper considered the toughest ever?+
The CAT 2004 retest is considered the toughest due to its extremely difficult Quantitative and LRDI sections, combined with the immense pressure on students after the original exam was cancelled. The overall cutoffs were significantly lower than in other years, reflecting the paper's high difficulty level.
Is solving old CAT LRDI sets useful for IPMAT?+
Absolutely. Solving select CAT LRDI sets, especially from the early 2000s, is excellent practice for IPMAT. These older sets focus on pure logical deduction rather than heavy calculation, which closely aligns with the reasoning skills tested in the IPMAT logical reasoning section.