Data Interpretation: Tables, Charts and Graphs Practice Questions for GATE DA: 15+ Solved Questions with Step-by-Step Solutions

Solve 15+ Data Interpretation: Tables, Charts and Graphs practice questions for GATE DA with answers and detailed solutions. Free sample questions below.

Chapter Roadmap: Data Interpretation

Chapter Journey: Data Interpretation

Step 1: Chart-Based Percentage and Average Interpretation

Focus: Pie charts, bar graphs, and line charts.

Core Skill: Converting visual proportions into exact percentages and weighted averages.

Weightage: High (Foundation for all DI questions).

Step 2: Grid and Matrix Data Counting

Focus: 2D arrays, pixel intensity matrices, and tabular conditions.

Core Skill: Systematic counting under multiple simultaneous constraints.

Weightage: Moderate (Requires careful, methodical checking).

Mastery Goal: You will learn to bypass visual deception and extract raw numerical truth from any chart or grid in under two minutes.

Topic Hero: The Core of Chart Interpretation

The Core Principle

Every chart interpretation problem reduces to a single mapping:

Visual Feature ↔ Numerical Value

Pie Chart: Angle or Area ↔ Percentage of Total

Bar/Line Chart: Height or Position ↔ Absolute Value or Frequency

The Golden Rule: Always identify the denominator (the total or base) before calculating any percentage or average. Charts often omit the total, requiring you to deduce it from a known segment's value and its visual proportion.

Data Interpretation: Tables, Charts and Graphs: Solved Questions with Step-by-Step Explanations (5 Problems)

Question 1 · Quantitative Aptitude MCQ

If the average value of a dataset $X$ is 10, and a new dataset $Y$ is created using the linear transformation $Y = 2 X + 3$ , what is the average value of $Y$ ?

A.
20
B.
13
C.
26
D.
23

Correct Answer:

Step-by-Step Solution

Key idea: This is a direct substitution question, recognisable because it gives the average of a variable and asks for the average after a linear transformation.

Step 1: Recall the property of linear transformation of averages. If $Y = a X + b$ , then the average of $Y$ is $\overset{ˉ}{Y} = a \overset{ˉ}{X} + b$ .

Step 2: Identify the given values. $\overset{ˉ}{X} = 10$ , $a = 2$ , and $b = 3$ .

Step 3: Substitute these values into the formula: $\overset{ˉ}{Y} = 2 (10) + 3$ .

Step 4: Calculate the result: $20 + 3 = 23$ .

Answer: D

Question 2 · Quantitative Aptitude MCQ

When interpreting a pie chart that explicitly shows the "share of valid votes", what is the correct base value to use for percentage calculations?

A.
Total votes cast minus invalid votes
B.
Total votes cast
C.
Total votes cast plus invalid votes
D.
The number of candidates

Correct Answer:

Step-by-Step Solution

Key idea: This is a definition question, recognisable because it asks for the correct baseline (denominator) when a chart specifies "valid" data.

Step 1: Read the chart title carefully. It specifies "share of valid votes".

Step 2: The pie chart represents parts of the "valid votes" whole.

Step 3: Therefore, the correct base value for any percentage calculation from this chart is the total number of valid votes, which is calculated as Total votes cast minus invalid votes.

Answer: A

Question 3 · Quantitative Aptitude MCQ

In an election data interpretation problem, if a pie chart represents the "share of valid votes", what is the correct base value to use when calculating a candidate's actual votes from their percentage?

A.
Valid votes (Total votes minus invalid votes)
B.
Total votes cast
C.
Invalid votes
D.
Average of total and invalid votes

Correct Answer:

Step-by-Step Solution

Key idea: This is a valid data baseline question, recognisable because it involves a pie chart of "valid votes" and requires finding the correct base for calculation.

Step 1: Identify that the pie chart percentages apply only to valid votes.

Step 2: The correct base is the total number of valid votes, which is calculated as Total votes minus invalid votes.

Answer: A

Question 4 · Quantitative Aptitude MCQ

When calculating the average number of patients per shift from a bar chart showing the frequency of different patient counts, what is the essential first step in the computation?

A.
Add all unique patient counts and divide by the number of bars
B.
Identify the maximum patient count
C.
Multiply each patient count by its corresponding frequency (number of shifts)
D.
Subtract the minimum patient count from the maximum

Correct Answer:

Step-by-Step Solution

Key idea: This is a frequency chart average computation question, recognisable because it asks for the procedure to find an average from grouped frequency data.

Step 1: Recall that an average from a frequency chart requires a weighted sum.

Step 2: The essential first step is to multiply each unique value (patient count) by its corresponding frequency (number of shifts) to get the weighted values.

Answer: C

Question 5 · Quantitative Aptitude MCQ

If the average of a dataset $X$ is $\overset{ˉ}{X}$ , and a new dataset $Y$ is formed by the transformation $Y = c X$ (where $c$ is a constant), what is the average of the new dataset $\overset{ˉ}{Y}$ ?

A.
$ar{X} + c$
B.
$car{X}$
C.
$rac{ar{X}}{c}$
D.
$ar{X}^c$

Correct Answer:

Step-by-Step Solution

Key idea: This is a linear transformation of averages question, recognisable because it asks for the new average after multiplying all data points by a constant.

Step 1: Recall the property of averages under scalar multiplication.

Step 2: If every data point in a set is multiplied by a constant $c$ , the average of the set is also multiplied by $c$ .

Step 3: Therefore, the new average is $\overset{ˉ}{Y} = c \overset{ˉ}{X}$ .

Answer: B

chapter

Data Interpretation: Tables, Charts and Graphs Practice Questions for GATE DA: 15+ Solved Questions with Step-by-Step Solutions

Solve 15+ Data Interpretation: Tables, Charts and Graphs practice questions for GATE DA with answers and detailed solutions. Free sample questions below.

A question from this chapter

Question 1

If the average value of a dataset X is 10, and a new dataset Y is created using the linear transformation Y = 2 X + 3, what is the average value of Y ?

Question 2

When interpreting a pie chart that explicitly shows the "share of valid votes", what is the correct base value to use for percentage calculations?

Question 3

In an election data interpretation problem, if a pie chart represents the "share of valid votes", what is the correct base value to use when calculating a candidate's actual votes from their percentage?

Question 4

When calculating the average number of patients per shift from a bar chart showing the frequency of different patient counts, what is the essential first step in the computation?

Question 5

If the average of a dataset X is \overset{ˉ}{X}, and a new dataset Y is formed by the transformation Y = c X (where c is a constant), what is the average of the new dataset \overset{ˉ}{Y} ?

Free preview ends here

Login to view the complete practice questions and solutions

Creating an account is free. You get the rest of this chapter, step-by-step solutions, and a study plan built around the topics you are actually weak at.

Why MastersUp

Personalised first. High quality throughout.

Most platforms hand everyone the same content. Here the content moves with your performance, topic by topic.

Built around you, not around a syllabus PDF

Every answer you give moves your topic-level intelligence rate. The next question, the next revision card and tomorrow's plan all change with it.

Revision that hits your weak spots

We only revise topics you have actually attempted and are still below the safe bar on — never the same chapter on repeat.

Questions calibrated to the real exam

Each question carries a measured toughness. You are served a rung above your current level, so practice keeps stretching you.

Notes written for recall, not for volume

Full lesson cards for first study, curated short-note cards for the last mile — with derivations, traps and exam patterns marked.

One place for everything

Notes, chapter practice, previous-year questions, test series and full-length papers — all feeding one picture of your preparation.

Honest progress

No vanity streaks. Progress here means chapters mastered and accuracy that held up on harder questions.

Unlock the whole course

Full notes and short notes, the complete question bank with worked solutions, mock tests, full-length papers, and an adaptive plan that rebuilds itself as you improve.

View all plans Start free