CAT 2021 Slot 2 Quantitative Ability Solutions & Strategies
Indian MBA Entrance Exam Analysis
The CAT (Common Admission Test) 2021 Slot 2 Quantitative Ability (QA) section included a mix of Data Interpretation (DI), Logical Reasoning (LR), and Quantitative Reasoning (QR) questions. Below is a breakdown of key topics, solved examples, and strategic tips for Indian test-takers.
1. Data Interpretation (DI)
Key Topics:
Caselet Analysis (2-3 questions)
Table/Graph Interpretation (1-2 questions)
Caselet + LR Hybrid (common in CAT).
Example Question:
A company sells three products—X, Y, Z. In 2020, sales were X: 120 units, Y: 150 units, Z: 180 units. In 2021, sales of X increased by 20%, Y decreased by 10%, and Z doubled. Calculate the overall percentage change in sales.
Solution:

2021 Sales:
X: (120 \times 1.2 = 144)
Y: (150 \times 0.9 = 135)
Z: (180 \times 2 = 360)
Total 2020: (120 + 150 + 180 = 450)
Total 2021: (144 + 135 + 360 = 639)
Percentage Change: (\frac{639 - 450}{450} \times 100 = 42.2%).
Strategy:
Quick Calculations: Use approximation (e.g., 20% of 120 ≈ 24 → 144).
Track Units: Avoid confusion between % increase and absolute values.
2. Logical Reasoning (LR)
Key Topics:
Pigeonhole Principle
Set Theory
Seating Arrangements
Example Question:
8 people (A, B, C, D, E, F, G, H) are seated in a row. Conditions:
A and B are adjacent.
C is not adjacent to D.
E and F are separated by exactly two people.
How many valid arrangements are there?*
Solution:
Total Arrangements: (8!).
Apply Constraints:
Treat A and B as a single unit → (2 \times 7!) (since A and B can switch places).
Subtract cases where C and D are adjacent: (2 \times 6!) (treat C and D as a unit).
Adjust for E and F: Place E and F with exactly two people between them.
Final Calculation: (2 \times 7! - 2 \times 6! + \text{valid E/F placements}).
Strategy:
Visual Mapping: Draw seating positions and mark constraints.
Inclusion-Exclusion: Systematically add/subtract overlaps.
3. Quantitative Reasoning (QR)
Key Topics:
Number Theory (LCM, HCF, Prime Factors)
Algebra (Quadratic Equations, Inequalities)
Probability
Example Question:
A bag contains 4 red, 5 blue, and 6 green balls. If 3 balls are drawn at random, what is the probability that at least one is red?
Solution:
Total Ways: (\binom{15}{3} = 455).
Complementary Probability:
Probability of no red balls = (\binom{11}{3} = 165).
Probability of at least one red = (1 - \frac{165}{455} = \frac{290}{455} ≈ 63.7%).
Strategy:
Complementary Approach: Often saves time vs. calculating all favorable cases.
Simplify Fractions: Cancel common factors early (e.g., 290/455 → 58/91).
4. Key Takeaways for Indian Aspirants
Time Management:
DI/LR questions (30-40 minutes) → Focus on accuracy.
QR questions (20-25 minutes) → Prioritize high-weightage topics (Number Theory, Algebra).
Common Pitfalls:
Misreading units (e.g., % vs. absolute values).
Overcomplicating LR problems (simplify constraints first).
Practice Resources:
Previous CAT papers (2018-2020).
Mock tests with adaptive timing.
Final Tips:
Mock Test Analysis: Identify weak areas (e.g., probability, permutations).
Formula sheets: Memorize key formulas (e.g., LCM-HCF, quadratic roots).
Stay Calm: CAT is designed to test strategic thinking—avoid panic in the last 10 questions.
For specific questions from Slot 2, share the problem statements for tailored solutions!
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CAT 2021 Analysis: Quantitative and Logical Mastery
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