📊 Meghalaya Patwari / Lekhpal – Quantitative Aptitude
Topic: Tables
1. Simple Explanation
A table in quantitative aptitude is a small, organized list of numbers arranged in rows and columns.
It is used to:
- Present data in a readable format.
- Quickly answer questions such as “What is the sum of the numbers in column 2?” or “How many rows have a value greater than 50 in column 3?”
When solving problems involving tables, treat them like a spreadsheet:
- Rows = items (e.g., villages, districts, years).
- Columns = attributes (e.g., population, area, revenue).
The key is to read the table carefully, identify the required data, and perform the arithmetic or comparison asked.
2. Key Points
| # | Concept | Why It Matters | Quick Tip |
|---|---|---|---|
| 1 | Table Structure | Understand what each row/column represents. | Read the heading first. |
| 2 | Data Types | Numbers can be integers, decimals, percentages, or ratios. | Note the unit (e.g., ₹, %, km²). |
| 3 | Missing Values | Sometimes a table has blanks; you may need to compute them. | Use given totals or relationships. |
| 4 | Summation & Averaging | Common operations: sum of a column, average of a row. | Use quick mental math for small tables. |
| 5 | Ratios & Proportions | Tables often show parts of a whole. | Convert percentages → fractions → decimals. |
| 6 | Comparative Questions | Find the maximum/minimum, count of entries above a threshold. | Scan the column, count mentally. |
| 7 | Percentage Change | Change from one year to another. | Δ% = [(New−Old)/Old] × 100. |
| 8 | Cross‑tabulation | Table with two categorical variables (e.g., gender vs. occupation). | Look for row/column totals. |
| 9 | Error Checking | Totals often equal sum of components. | Verify quick addition to spot mistakes. |
| 10 | Time Management | Tables can be dense; skim for relevant numbers. | Focus on the column/row specified in the question. |
3. Worked Example
Problem
A table below shows the annual revenue (in ₹ Lakhs) of five villages from 2019 to 2021.
| Village | 2019 | 2020 | 2021 |
|---|---|---|---|
| A | 120 | 135 | 150 |
| B | 80 | 90 | 95 |
| C | 200 | 210 | 250 |
| D | 50 | 55 | 60 |
| E | 110 | 120 | 115 |
Questions
- What is the total revenue of all villages in 2020?
- Which village had the highest revenue in 2021?
- By what percentage did the revenue increase from 2019 to 2021 for Village C?
- How many villages had a revenue greater than ₹ 100 Lakhs in 2019?
Solution
| Step | Action | Result |
|---|---|---|
| 1 | Sum column 2020 | 135 + 90 + 210 + 55 + 120 = 610 Lakhs |
| 2 | Compare 2021 values | A = 150, B = 95, C = 250, D = 60, E = 115 → Village C highest |
| 3 | Percentage change for C | ((250−200)/200) × 100 = 50/200 × 100 = 25 % |
| 4 | Count >100 in 2019 | A =120, B =80, C =200, D =50, E =110 → 3 villages (A, C, E) |
Answers
- ₹ 610 Lakhs
- Village C
- 25 % increase
- 3 villages
Quick Check
- Totals add up correctly.
- Percentage calculation uses the 2019 value as the base.
- Counting >100 is straightforward.
4. Quick Revision Summary
| Topic | What to Remember |
|---|---|
| Table reading | Start with headings → identify rows and columns. |
| Missing data | Use totals or other relationships to fill blanks. |
| Summation | Add column/row values; double‑check with quick mental math. |
| Ratios & percentages | Convert to fractions or decimals; use 100‑% as base. |
| Comparative queries | Scan for max/min, count above/below a value. |
| Percentage change | Δ% = [(New−Old)/Old] × 100. |
| Error spotting | Row/column totals should match given totals. |
| Speed tip | Read only the column/row asked; ignore irrelevant data. |
Final Tip for Exam Day
- Read the question first to know which part of the table you need.
- Use pencil to underline or circle relevant numbers.
- Check calculations quickly—especially sums and percentages.
Happy studying! 🚀