Data Interpretation (DI): Comprehensive Notes, Concepts, and 100 Practice Questions with Answers

1. What is Data Interpretation (DI)?

Data Interpretation is a quantitative aptitude topic that tests your ability to analyze and interpret data presented in various formats—tables, bar graphs, pie charts, line graphs, and caselets. You must extract relevant information, perform calculations, and answer questions accurately and quickly, a skill crucial for exams like IBPS, SBI, CAT, and other competitive tests1 78.

2. Types of DI Questions

A. Tables

Description: Data is organized in rows and columns.
Approach: Read headings carefully, note units, and use row/column totals if needed.
Example:
Year Sales (₹ lakh) Expenses (₹ lakh)
2022 50 30
2023 60 35

B. Bar Graphs

Description: Data shown as rectangular bars, height/length represents value.
Approach: Compare bar heights, note scale and units.
Example:
Students in Classes: A (30), B (40), C (35), D (25), E (20).

C. Pie Charts

Description: Data as sectors of a circle, often in percentages or degrees.
Approach: Find total, convert sectors to values using percentage or angle.
Example:
If a sector is 90°, it represents 25% (since 360° = 100%).

D. Line Graphs

Description: Data points connected by lines, showing trends over time.
Approach: Note axis labels, find increases/decreases, compare values.

E. Caselets

Description: Data is given in a paragraph, not as a chart or table.
Approach: Read carefully, extract and organize data into a table or list for easier analysis56.

F. Data Sufficiency

Description: Given statements, determine if the data is enough to answer a question.
Approach: Analyze each statement alone and together; do not solve, just check sufficiency3.

3. Key Strategies for DI

Read all instructions and data carefully.
Identify what is being asked: totals, averages, ratios, percentages, differences, etc.
Extract and organize data: Make your own table if needed, especially for caselets.
Check units and conversions: Be careful with thousands, lakhs, percentages, degrees in pie charts, etc.
Estimate when possible: Useful for eliminating answer choices quickly1 3 4 56.
Practice calculation speed: Many DI sets are calculation-intensive.

4. Solved Examples

Table Example

Year	Sales (₹ lakh)	Expenses (₹ lakh)
2022	50	30
2023	60	35

Q: What is the profit in 2023?
A: ₹60 lakh - ₹35 lakh = ₹25 lakh.

Bar Graph Example

If bars show: A (20), B (25), C (30), D (15), E (10).
Q: What is the average?
A: (20 + 25 + 30 + 15 + 10)/5 = 20.

Pie Chart Example

If a sector is 72°, what percent is this?
A: 72/360 × 100 = 20%.

Line Graph Example

If Jan = 100, Feb = 150, Mar = 200, what is the increase from Jan to Mar?
A: 200 - 100 = 100.

Caselet Example

"A company has 100 employees: 60 are male, 40 are female. 30 males and 10 females are managers."
Q: What percent of managers are male?
A: Total managers = 30 + 10 = 40.
Percent male = 30/40 × 100 = 75%.

Data Sufficiency Example

Q: What is the value of x?
I. x + 2y = 10
II. y = 3
A: Both statements together are sufficient.

5. 100 Practice Questions with Answers and Explanations

Tables

Table: Yearly sales of a company for 5 years are 120, 140, 110, 130, 150. What is the average sales?
Ans: (120+140+110+130+150)/5 = 650/5 = 130
Table: If profit in 2022 is ₹30 lakh and expenses are ₹20 lakh, what is the profit percentage?
Ans: (30-20)/20 × 100 = 50%
Table: Employees in Depts A, B, C: 50, 70, 80. What is the total?
Ans: 200
Table: If sales in Q1 = 100, Q2 = 120, Q3 = 110, which quarter had the highest?
Ans: Q2
Table: If 40% of 200 employees are female, how many are male?
Ans: 60% of 200 = 120
Table: If revenue in 2021 was ₹80 lakh and in 2022 ₹100 lakh, what is the percentage increase?
Ans: (100-80)/80 × 100 = 25%
Table: If expenses in 2023 are ₹45 lakh and sales are ₹60 lakh, what is the profit?
Ans: ₹15 lakh
Table: If total students in 5 classes are 30, 35, 40, 25, 20, what is the median?
Ans: 30
Table: If 25% of 400 products are defective, how many are not defective?
Ans: 75% of 400 = 300
Table: If the highest value is 180 and the lowest is 120, what is the difference?
Ans: 60

Bar Graphs

Bar graph: If bars show 10, 20, 30, 40, what is the sum?
Ans: 100
Bar graph: If A = 25, B = 35, C = 40, what is the ratio A:B?
Ans: 25:35 = 5:7
Bar graph: If the tallest bar is 50 and the shortest is 10, what is the difference?
Ans: 40
Bar graph: If the average of five bars is 24, what is the total?
Ans: 24 × 5 = 120
Bar graph: If bars represent sales in 5 years and the lowest is in year 3, which year is that?
Ans: Year 3
Bar graph: If sales in year 1 and year 2 are 30 and 40, what is the percentage increase?
Ans: (40-30)/30 × 100 = 33.33%
Bar graph: If the sum of all bars is 200 and there are 4 bars, what is the average?
Ans: 200/4 = 50
Bar graph: If the second bar is twice the first, and the first is 15, what is the second?
Ans: 30
Bar graph: If bars are 12, 18, 24, 30, what is the median?
Ans: (18+24)/2 = 21
Bar graph: If the difference between the highest and lowest is 25, and the lowest is 10, what is the highest?
Ans: 35

Pie Charts

Pie chart: If a sector is 90°, what percent is this?
Ans: 25%
Pie chart: If total sales are ₹80,000 and a sector is 20%, what is the value?
Ans: 0.2 × 80,000 = ₹16,000
Pie chart: If sector A is 72°, sector B is 108°, what is the ratio A:B?
Ans: 72:108 = 2:3
Pie chart: If a sector is 60°, what percent is this?
Ans: 60/360 × 100 = 16.67%
Pie chart: If the largest sector is 120°, what is the percentage?
Ans: 120/360 × 100 = 33.33%
Pie chart: If total is ₹1,00,000 and a sector is 30%, what is the value?
Ans: ₹30,000
Pie chart: If sector A is 25%, sector B is 35%, what is the difference in value if total is ₹40,000?
Ans: (0.35 - 0.25) × 40,000 = ₹4,000
Pie chart: If a sector is 45°, what percent is this?
Ans: 12.5%
Pie chart: If two sectors are 90° and 180°, what is their combined percent?
Ans: (90+180)/360 × 100 = 75%
Pie chart: If total is 800 units and a sector is 18%, how many units?
Ans: 0.18 × 800 = 144

Line Graphs

Line graph: If sales in Jan = 100, Feb = 150, Mar = 200, what is the increase from Jan to Mar?
Ans: 100
Line graph: If the highest point is 220 and the lowest is 90, what is the difference?
Ans: 130
Line graph: If values for 6 months are 100, 120, 140, 160, 180, 200, what is the average?
Ans: 150
Line graph: If the value increases by 20 each month, what is the value in the 5th month if the first is 60?
Ans: 60 + 4×20 = 140
Line graph: If the sum of all points is 600 and there are 4 points, what is the average?
Ans: 150
Line graph: If the value drops from 200 to 160, what is the percentage decrease?
Ans: (200-160)/200 × 100 = 20%
Line graph: If the highest is 180, the second highest is 150, what is the difference?
Ans: 30
Line graph: If the lowest is 90, the highest is 210, what is the range?
Ans: 120
Line graph: If the value in April is 120 and in May is 180, what is the increase?
Ans: 60
Line graph: If the sum of values in Jan, Feb, Mar is 330, what is the average?
Ans: 110

Caselets

In a company of 120 employees, 70 are male, 50 are female. 40 males and 20 females are managers. What percent of managers are female?
Ans: 20/(40+20) × 100 = 33.33%
In a school, 60% of 200 students are boys. How many girls?
Ans: 40% of 200 = 80
In a class of 50, 20% scored above 90. How many students is that?
Ans: 10
In a batch of 100, 30% failed. How many passed?
Ans: 70
In a survey, 40% like tea, 60% like coffee. If 200 surveyed, how many like tea?
Ans: 80
In a group, 120 people, 1/3 are engineers. How many engineers?
Ans: 40
In a batch, 25% are girls, rest boys. If 80 students, how many boys?
Ans: 60
In a company, 10% are managers, 20% are team leads, rest are employees. If 300 total, how many employees?
Ans: 70% of 300 = 210
In a test, 60% scored above 50, 30% between 30-50, rest below 30. If 200 students, how many below 30?
Ans: 10% of 200 = 20
In a class, 1/4 are absent. If 40 present, how many students in total?
Ans: If 3/4 = 40, total = 40 × 4/3 = 53.33 ≈ 54

Data Sufficiency

What is x?
I. x + 3 = 7
II. x - 2 = 2
Ans: Either I or II alone is sufficient.
Is y even?
I. y = 2x, x is integer
II. y = 4
Ans: Either I or II alone is sufficient.
What is the value of z?
I. z + 2 = 8
II. z × 2 = 12
Ans: Either I or II alone is sufficient.
Is a > b?
I. a = 5, b = 3
II. a - b = 2
Ans: Either I or II alone is sufficient.
Is n divisible by 4?
I. n = 8
II. n = 12
Ans: Either I or II alone is sufficient.
What is the sum of x and y?
I. x = 5
II. y = 3
Ans: Both together are sufficient.
Is m positive?
I. m > 0
II. m + 2 = 5
Ans: Either I or II alone is sufficient.
Is p a prime number?
I. p = 7
II. p = 9
Ans: I alone is sufficient.
What is the average of a, b, c?
I. a + b + c = 18
II. a = 5, b = 7, c = 6
Ans: Either I or II alone is sufficient.
Is x > 0?
I. x^2 > 0
II. x = -1
Ans: Neither alone is sufficient.

Mixed DI Questions

Table: If 30% of products are defective in a batch of 500, how many are not defective?
Ans: 350
Bar graph: If the sum of all five bars is 250, what is the average?
Ans: 50
Pie chart: If a sector is 54°, what percent is this?
Ans: 15%
Line graph: If the highest value is 210 and the lowest is 90, what is the range?
Ans: 120
Caselet: In a group of 80, 25% are absent. How many present?
Ans: 60
Data sufficiency: Is x odd?
I. x = 5
II. x = 6
Ans: I alone is sufficient.
Table: If 40% of employees are female in a company of 250, how many males?
Ans: 150
Bar graph: If the average is 32 and there are 4 bars, what is the sum?
Ans: 128
Pie chart: If sector is 108°, what percent is this?
Ans: 30%
Line graph: If the sum of values in Jan, Feb, Mar is 600, what is the average?
Ans: 200
Table: If 20% of 400 products are defective, how many are not defective?
Ans: 320
Bar graph: If the highest bar is 80 and the lowest is 20, what is the difference?
Ans: 60
Pie chart: If sector is 45°, what percent is this?
Ans: 12.5%
Line graph: If the value in April is 120 and in May is 180, what is the increase?
Ans: 60
Caselet: In a test, 70% scored above 50, 20% between 30-50, rest below 30. If 300 students, how many below 30?
Ans: 10% of 300 = 30
Data sufficiency: Is y negative?
I. y = -2
II. y^2 = 4
Ans: I alone is sufficient.
Table: If the highest value is 200 and the lowest is 100, what is the difference?
Ans: 100
Bar graph: If the average is 24 and there are 5 bars, what is the sum?
Ans: 120
Pie chart: If two sectors are 90° and 180°, what is their combined percent?
Ans: 75%
Line graph: If the sum of values in Jan, Feb, Mar is 330, what is the average?
Ans: 110

Advanced DI Sets (Tables, Graphs, Caselets)

81–100. (Create your own DI sets: Provide a small table, bar graph, pie chart, or caselet and ask 5 questions per set. Example below.)

Table Set:

Year	Sales	Profit
2021	100	20
2022	120	25
2023	140	35

What is the average sales?
Ans: (100+120+140)/3 = 120
What is the total profit?
Ans: 20+25+35 = 80
What is the profit percentage in 2023?
Ans: 35/140 × 100 = 25%
What is the increase in sales from 2021 to 2023?
Ans: 40
What is the average profit percentage over 3 years?
Ans: (20/100 + 25/120 + 35/140)/3 × 100 ≈ (20% + 20.83% + 25%)/3 ≈ 21.94%

Bar Graph Set:
If bars show: A (20), B (30), C (40), D (50), E (60).

What is the total?
Ans: 200
What is the average?
Ans: 40
Which bar is the highest?
Ans: E
What is the difference between highest and lowest?
Ans: 40
What is the ratio of C to A?
Ans: 2:1

Pie Chart Set:
If sectors are 90°, 120°, 60°, 90°.

What percent is the largest sector?
Ans: 120/360 × 100 = 33.33%
What is the combined percent of the two 90° sectors?
Ans: 50%
If total is 600 units, what is the value for the 60° sector?
Ans: 100
What is the difference in value between the largest and smallest sector?
Ans: (120-60)/360 × 600 = 100
What is the ratio of the smallest to the largest sector?
Ans: 1:2

Caselet Set:
A company has 3 departments: HR (30), Sales (50), IT (20). 40% of HR are female, 60% of Sales are male, IT is all male.

How many females in HR?
Ans: 12
How many males in Sales?
Ans: 30
What percent of the company is in IT?
Ans: 20%
What is the total number of employees?
Ans: 100
What percent of all employees are female?
Ans: (12 + 20 (Sales females))/100 = 32%

For more DI sets, download free PDFs and quizzes from Smartkeeda, Byjus, and practice regularly to master all formats1 2 3 4 5 6 78.

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