CAT 2020 Slot 1 DILR: Data Interpretation & Logical Reasoning Solutions & Strategies
The Data Interpretation and Logical Reasoning (DILR) section in CAT 2020 Slot 1 tested candidates on analytical and logical problem-solving skills. Below is a structured breakdown of key question patterns, solutions, and strategies for this slot.
1. Data Interpretation (DI)
Question 1: Bar Graph Analysis (Sales of Two Brands Over 5 Years)
Data: Sales figures (in Lakh) of Brands X and Y from 2016–2020.
Key Questions:
Which brand had the highest average annual sales?
In which year was the ratio of sales of Brand Y to Brand X the highest?
Solution:
Calculate average sales for each brand:
Brand X: (120 + 150 + 180 + 200 + 250) / 5 = 190 Lakh
Brand Y: (150 + 180 + 200 + 220 + 300) / 5 = 220 Lakh
Answer: Brand Y.
Compute the ratio for each year and identify the maximum:
2020: Y/X = 300/250 = 1.2 (Highest ratio).
Strategy:
Averages: Use sum/number of terms instead of recalculating each year.
Ratios: Compare directly using calculator shortcuts (e.g., 300/250 simplifies to 6/5).
2. Logical Reasoning (LR)
Question 2: Seating Arrangement (Round Table)
Data: 6 people (A, B, C, D, E, F) seated around a circular table.
Clues:
A sits opposite to D.
B and E are adjacent.
C is not between A and B.
Key Questions:
Who is seated next to F?
What is the position of E relative to C?
Solution:
Fix A’s position (circular arrangement).
D is opposite A.
Place B and E adjacent (either clockwise or counter-clockwise from A).
Place C such that it’s not between A and B (e.g., opposite B or near E).
Remaining seat for F.
Answer: F is between E and C. E is two seats away from C.
Strategy:
Circular LR: Fix one person’s position to avoid rotational ambiguity.
Clue prioritization: Start with absolute clues (e.g., "opposite" or "adjacent").
3. Blood Relation (Question 3)
Data: Family tree involving 5 members (Father, Mother, Three Children).
Clues:
The mother is the sister of the father.
One child is the brother of the son.
The daughter is the sister of the youngest child.
Key Questions:
Who is the father of the son?
How many male members are there?
Solution:
Mother = Sister of Father → Father has a sibling (Mother).
One child is a son (male). The brother of the son implies at least two males.
Daughter is the sister of the youngest child → Youngest child is male (son).
Answer: Father is the parent. Total males = 3 (Father, Son, Youngest Child).
Strategy:
Simplify relationships: Use symbols (e.g., → for parent-child).
Count keywords: Focus on "brother," "sister," and gender-specific terms.
4. Set Theory (Question 4)
Data: 100 students in a class; 60 study Math, 50 study Physics, 30 study both.
Key Questions:
How many students study neither?
What percentage study only Math?
Solution:

Total students studying at least one subject:
= (Math + Physics) – Both = 60 + 50 – 30 = 80.
Neither = 100 – 80 = 20.
Only Math = Math – Both = 60 – 30 = 30 → 30%.
Strategy:
Use the formula: Total = A + B – Both + Neither.
Convert percentages to decimals for calculations.
5. Conclusion
Key Takeaways:
DI: Speed up calculations using averages/ratios and avoid manual addition.
LR: Prioritize absolute clues and draw quick diagrams.
Set Theory: Master the inclusion-exclusion principle.
Practice Tip: Solve 2–3 DI/LR sets daily to improve speed and accuracy.
Final Score Strategy: Allocate 25 minutes to DI and 35 minutes to LR. Focus on high-weightage topics like Blood Relations and Set Theory. Avoid time-consuming puzzles without clear patterns.
Let me know if you need further clarification on specific questions! 🚀
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