Study Material — 51 PYQs (2018–2020) · Concept Notes · Shortcuts
NDA Bar Charts is a frequently tested subtopic — 51 previous year questions from 2018–2020 papers are included below with concept notes, key rules and shortcut tricks.
51 questions from actual NDA papers · all shown free · click option to reveal solution
Exam Q 12019Previous Year Pattern
What is the percentage increase in sales of Beta from Q1 to Q4?
Exam Q 22019Previous Year Pattern
What is the total sales of Alpha company across all four quarters?
Exam Q 32019Previous Year Pattern
What is the average quarterly sales of Delta company?
Exam Q 42019Previous Year Pattern
By what percentage did Product E's sales increase from Q1 to Q4?
Exam Q 52020Previous Year Pattern
What is the ratio of Q4 sales of Books & Media to Q4 sales of Sports & Outdoors?
Exam Q 62020Previous Year Pattern
By what percentage did Store B's sales increase from January to May?
Exam Q 72020Previous Year Pattern
Which store showed a consistent decrease in sales from January to May?
Exam Q 82020Previous Year Pattern
What is the average monthly sales of Store D over the five months?
Exam Q 92020Previous Year Pattern
What is the difference between the total sales of Store E and Store C over all five months?
Exam Q 102020Previous Year Pattern
Which product category had the highest total sales across all four quarters?
Exam Q 112020Previous Year Pattern
By what percentage did Clothing sales increase from Q1 to Q4?
Exam Q 122020Previous Year Pattern
What is the total sales of Electronics category across all four quarters?
Exam Q 132019Previous Year Pattern
What is the total sales of Product A across all four quarters?
Exam Q 142020Previous Year Pattern
What is the total sales of Store A across all five months?
Exam Q 152019Previous Year Pattern
Which company has the highest sales in Q3?
Exam Q 162019Previous Year Pattern
Which product has the highest sales in Q4?
Exam Q 172019Previous Year Pattern
What is the average quarterly sales of Product C?
Exam Q 182019Previous Year Pattern
What is the ratio of Q2 sales of Gamma to Q2 sales of Delta?
Exam Q 192019Previous Year Pattern
What is the ratio of Q2 sales of Product B to Q2 sales of Product D?
Exam Q 202019Previous Year Pattern
What is the average quarterly sales for Books across all four quarters?
Exam Q 212018Previous Year Pattern
In which year was the total combined sales of all five companies the highest, and what was that total (in ₹ Lakhs)?
Exam Q 222019Previous Year Pattern
In Q2, what is the difference between total sales of Smartphones and Tablets combined versus Software and Accessories combined (in lakhs)?
Exam Q 232020Previous Year Pattern
What is the ratio of Q4 sales of Alpha to Q4 sales of Gamma?
Exam Q 242018Previous Year Pattern
What is the ratio of total sales of Company A to total sales of Company C over all four years?
Exam Q 252019Previous Year Pattern
By what percentage did Smartphones sales increase from Q1 to Q4?
Exam Q 262019Previous Year Pattern
What is the ratio of Q2 sales of Home & Kitchen to Q2 sales of Sports?
Exam Q 272019Previous Year Pattern
By what percentage did Electronics sales increase from Q1 to Q4?
Exam Q 282018Previous Year Pattern
The sales of Company B in 2021 is what percentage more or less than the sales of Company D in the same year?
Exam Q 292018Previous Year Pattern
In 2022, the combined sales of Company A and Company D is what percentage of the combined sales of Company B and Company E in the same year?
Exam Q 302019Previous Year Pattern
What is the total sales revenue for the Clothing category across all four quarters?
Exam Q 312020Previous Year Pattern
What is the percentage increase in sales of Epsilon from Q1 to Q4?
Exam Q 322018Previous Year Pattern
What is the average sales (in ₹ Lakhs) of Company C over all four years?
Exam Q 332019Previous Year Pattern
In Q3, which product category had sales equal to 50% of Electronics sales in that quarter?
Exam Q 342019Previous Year Pattern
What is the ratio of Q3 sales of Tablets to Q3 sales of Accessories?
Exam Q 352018Previous Year Pattern
What is the ratio of total sales of Company A to total sales of Company B over all four years?
Exam Q 362019Previous Year Pattern
What is the average quarterly sales (in lakhs) for Laptops across all four quarters?
Exam Q 372018Previous Year Pattern
What is the percentage increase in sales of Company E from 2019 to 2022?
Exam Q 382018Previous Year Pattern
The sales of Company A in 2023 is what percentage more than the sales of Company E in 2022?
Exam Q 392019Previous Year Pattern
Which product category shows a consistent quarter-on-quarter growth of exactly 30 lakhs in each quarter?
Exam Q 402020Previous Year Pattern
What is the average Q2 sales across all five companies?
Exam Q 412018Previous Year Pattern
By what percentage did the sales of Company D increase from 2020 to 2023?
Exam Q 422018Previous Year Pattern
In which year was the combined sales of Company B and Company E together the highest?
Exam Q 432018Previous Year Pattern
What is the ratio of total sales revenue of Alpha in 2020 and 2021 combined to the total sales revenue of Beta in 2022 and 2023 combined?
Exam Q 442019Previous Year Pattern
By what percentage did Home & Kitchen sales increase from Q1 to Q4?
Exam Q 452019Previous Year Pattern
What is the average quarterly sales of Sports & Outdoors across all four quarters?
Exam Q 462019Previous Year Pattern
What is the ratio of total sales of Electronics in Q1 and Q2 combined to total sales of Clothing in Q3 and Q4 combined?
Exam Q 472019Previous Year Pattern
By what percentage did the sales of Clothing category increase from Q1 to Q4?
Exam Q 482019Previous Year Pattern
In Q3, what is the difference between the combined sales of Electronics and Home & Kitchen and the combined sales of Books & Media and Sports & Outdoors?
Exam Q 492019Previous Year Pattern
What is the ratio of total annual sales of Electronics to total annual sales of Books & Media?
Exam Q 502019Previous Year Pattern
What is the average quarterly sales of Home & Kitchen category for the entire year?
Exam Q 512019Previous Year Pattern
In Q3, which product category's sales were closest to the average sales of all categories in that quarter?
Concept Notes
Bar Charts— Rules & Concept
Core ConceptRead this first — the foundation of the topic
BAR CHARTS — COMPLETE GUIDE FOR SSC CGL ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
CORE CONCEPT ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
A bar chart is a graph that uses rectangular bars to show data. Each bar represents one category or time period. The HEIGHT (or LENGTH) of the bar shows the VALUE of that category. Bars can be vertical (column chart) or horizontal. In SSC CGL, bar charts appear in almost every paper — usually 4 to 5 questions per set. You are given a bar chart and asked to find totals, averages, percentage change, ratios, or differences between values. The data is READ from the bar heights using the Y-axis scale.
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Key RulesCore rules you must know cold
1
Always read the Y-axis scale carefully. Check if values are in units, thousands, lakhs, or crores.
2
Grouped bar charts show multiple bars side by side for one category — compare bars within the same group.
3
Stacked bar charts pile bars on top of each other — read individual segments carefully.
4
The X-axis usually shows categories (years, months, products, departments).
5
Never assume values — always calculate from the scale.
Formula BlockMemorise — at least one formula appears in every paper
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Percentage Change = ((New Value - Old Value) / Old Value) x 100
Average = Sum of all values / Number of values
Ratio = Value A : Value B (simplify by dividing both by HCF)
Percentage Share = (Individual Value / Total Value) x 100
Difference = Larger value - Smaller value
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Exam PatternsWhat examiners ask — read before attempting PYQs
Learn these
Pattern 1 — Percentage Increase/Decrease: Compare two bars and find % change
Pattern 2 — Average
Add values of given years and divide by count
Pattern 3 — Ratio
Write two bar values as a fraction and simplify
Pattern 4 — Total
Add all bars or selected bars
Pattern 5 — Difference
Subtract one bar value from another
Pattern 6 — Percentage Share
One bar as % of total of all bars.
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ShortcutsUse these to save 30–60 seconds per question
Common fractions to memorise
1/4=25%, 1/5=20%, 1/3=33.33%, 1/6=16.67%, 1/8=12.5%
TRICK 2 — AVERAGE SHORTCUT:
Instead of adding all values and dividing, pick any one value as BASE. Find how much each other value is above or below the base. Average the differences and add/subtract from base
Example
Values are 200, 220, 180, 240, 210. Pick base = 200
Differences
0, +20, -20, +40, +10. Sum of differences = +50. Average difference = 50/5 = 10. Average = 200 + 10 = 210
TRICK 3 — RATIO SIMPLIFICATION
Always divide both values by their HCF immediately. If bars show 240 and 360, HCF = 120. Ratio = 2:3
Do not leave ratios as 240
360 — examiners test your simplification.
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Worked ExampleSolve this step-by-step before moving on
1
Step 1
Find the change. Change = 650 - 500 = 150
2
Step 2
Divide by the OLD value (base year). 150 / 500 = 3/10
3
Step 3
Multiply by 100. 3/10 x 100 = 30%
Answer: 30% increase
Key point: Always divide by the OLD (earlier) value, NOT the new value.
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WORKED EXAMPLE 2 — AVERAGE AND RATIO
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Question: A bar chart shows production (in thousands) for 5 years: 2018=40, 2019=60, 2020=50, 2021=80, 2022=70. (A) Find the average production. (B) Find the ratio of production in 2019 to 2022.
Part A — Average:
1
Step 1
Add all values. 40 + 60 + 50 + 80 + 70 = 300
2
Step 2
Divide by number of years. 300 / 5 = 60
Answer: Average = 60 thousand units
Part B — Ratio:
1
Step 1
Write values. 2019 = 60, 2022 = 70
2
Step 2
Ratio = 60:70
3
Step 3
HCF of 60 and 70 = 10. Divide both. 60/10 : 70/10 = 6:7
Answer: Ratio = 6:7
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Exam TrapsCommon mistakes students make — avoid these
— NUMBER 1 TRAP
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MOST COMMON TRAP: Students use the WRONG BASE in percentage change questions.
For PERCENTAGE INCREASE — divide by the SMALLER (earlier) value.
For PERCENTAGE DECREASE — divide by the LARGER (earlier) value.
Both cases: always divide by the ORIGINAL (starting) value.
Example of the trap: If value drops from 500 to 400, wrong answer = 100/400 x 100 = 25% decrease. Correct answer = 100/500 x 100 = 20% decrease. The trap answer option 25% will always be in the choices to fool you.
Always use the starting value as your base.
Key Points to Remember
Bar height = value of that category; always read Y-axis scale and unit (units/thousands/lakhs/crores) first.
Percentage Change formula: ((New - Old) / Old) x 100 — always divide by the OLD value.
Average shortcut: Pick a base value, find deviations of other values, average the deviations, add to base.
Always simplify ratios by dividing both values by their HCF immediately.
Percentage Share formula: (Individual bar value / Sum of all bars) x 100.
Grouped bar chart: Compare bars within the same group; stacked bar chart: read each segment separately.
Six fixed question patterns in SSC CGL: % change, average, ratio, total, difference, percentage share.
Trap: In % decrease questions, the wrong base answer is always included as an option — always use the starting (original) value.
For average of selected bars only: add ONLY the specified bars, divide by ONLY that count — do not include all bars.
Exam-Specific Tips
In SSC CGL Tier-1, Data Interpretation carries 4-5 questions per set and typically 1-2 sets appear per paper, making it 4-10 marks per exam.
Percentage Change = ((New Value - Old Value) / Old Value) x 100 — this single formula covers both increase and decrease questions.
1/8 = 12.5%, 1/6 = 16.67%, 1/5 = 20%, 1/4 = 25%, 1/3 = 33.33% — these fraction shortcuts appear directly in bar chart percentage questions.
In a stacked bar chart, the value of a segment = top boundary of that segment MINUS the bottom boundary of that segment on the Y-axis scale.
Percentage Share of one category = (Value of that bar / Total of all bars) x 100 — result must be between 0% and 100%.
If a bar chart uses scale 'in thousands', a bar reading of 45 on the Y-axis means the actual value is 45,000 — ignoring the unit multiplier is a direct cause of wrong answers.
The average of n bar values = Sum of all n bar values divided by n — do not include bars from outside the specified range.
Ratio questions in bar charts always require final simplification; unsimplified ratios like 240:360 are always wrong answer options designed as traps.
Practice MCQs
Bar Charts — Practice Questions
70graded MCQs · easy to hard · full solution & trap analysis · showing 20 of 70
Remember: Always check the Y-axis unit FIRST — values may be in thousands or lakhs; multiply your reading by that unit before calculating.
Formula: Percentage Change = ((New - Old) / Old) x 100 — OLD value is ALWAYS the denominator, no exceptions.
Trap: In % decrease questions, the option using the new (smaller) value as base will always appear — reject it; use the original starting value.
Shortcut: Use fraction conversions (1/5=20%, 1/4=25%, 1/3=33.33%) to find percentages mentally without long division.
Formula: Average = Sum of selected bars / Count of selected bars — include only the bars specified in the question.
Remember: Simplify every ratio by HCF before matching with options — 60:70 must become 6:7 or you will miss the answer.
Trap: In grouped/stacked bar charts, read the correct bar or segment — misreading the wrong bar is the second most common error after wrong base in percentage.