The Mathematics of -0.25 Negative Deduction
In the C-CAT examination pattern, each question carries 1 mark. For every incorrect choice, 0.25 marks are deducted.
This means four incorrect answers cancel out one correct answer.
Mathematical Comparison
Consider two candidates answering a 50-question section:
- Candidate X (Calculated Attempts): Attempts 40 questions. Correct: 36. Wrong: 4.
- Score:
36 − (4 × 0.25) = 36 − 1.0 =35.0 Marks - Candidate Y (Blind Guessing): Attempts all 50 questions. Correct: 36. Wrong: 14.
- Score:
36 − (14 × 0.25) = 36 − 3.5 =32.5 Marks
Result: A difference of 2.5 marks in C-CAT can shift your position by hundreds of ranks, determining whether you receive admission to your preferred centre in Round 1 or must wait for subsequent rounds.
The Bottom 10% Disqualification Rule
Under C-DAC’s published admission guidelines:
*"Candidates with the lowest 10% performances in Section A, Section B, and Section C of C-CAT will not be qualified for ranking. Furthermore, candidates with zero or less than zero marks in any section will also not be ranked."*
This enforces two critical rules:
- You cannot skip or abandon any mandatory section.
- Scoring zero or negative marks in Section A or Section B automatically disqualifies you from the entire C-CAT admission process.
Smart Guessing vs Blind Guessing
1. Blind Guessing (1 in 4 chance)
- Random probability: 25% chance of correct (+1), 75% chance of wrong (-0.25).
- Expected Value =
(0.25 × 1) − (0.75 × 0.25) = 0.25 − 0.1875 = +0.0625. - While marginally positive in pure probability, the risk of cluster errors makes blind guessing hazardous for ranking stability.
2. Educated Guessing (After eliminating 2 options)
- 50% chance of correct (+1), 50% chance of wrong (-0.25).
- Expected Value =
(0.50 × 1) − (0.50 × 0.25) = 0.50 − 0.125 = +0.375. - If you can confidently eliminate 2 of the 4 options, making an educated guess is statistically beneficial.
Recommended Attempt Rates per Section
| Section | Conservative Target | High-Rank Target | Maximum Acceptable Errors |
|---|---|---|---|
| Section A (Aptitude) | 36–40 Attempts | 42–46 Attempts | ≤ 4 Wrong |
| Section B (CS Fundamentals) | 35–38 Attempts | 40–44 Attempts | ≤ 3 Wrong |
| Section C (Hardware) | 30–35 Attempts | 38–42 Attempts | ≤ 4 Wrong |
❓ Frequently Asked Questions
How does negative marking work in CDAC C-CAT?
Each question carries 1 mark. For every incorrect response, 0.25 marks are deducted (a 25% penalty). Unattempted questions carry zero marks.
Can I qualify if I score zero marks in one section?
No. C-DAC rules state that candidates with zero or negative marks in any individual section are automatically disqualified from the rank list.
Practice Mock Tests with Real C-CAT Pattern
Prepare with exam-level timer, negative marking simulation (−0.25 penalty), and section-wise analytics built by Sunbeam toppers.