GRE Data Interpretation Questions Practice Questions with Answers

Concept Explanation

GRE Data Interpretation questions are a specific subset of the Quantitative Reasoning section that require test-takers to analyze data presented in tables, graphs, or charts and perform calculations based on that information. These questions evaluate your ability to synthesize visual information, identify trends, and apply mathematical concepts like percentages, ratios, and averages to real-world data sets. Unlike standard word problems, the primary challenge here is locating the correct data point within a complex visual display before applying any formulas. Most GRE Prep strategies emphasize that while the underlying math is often basic arithmetic, the presentation of the data is designed to test your precision and attention to detail.

According to the Educational Testing Service (ETS), data interpretation accounts for approximately 25% of the Quantitative Reasoning section. You will typically encounter data sets followed by two to four questions. The most common formats include bar graphs, line graphs, pie charts, scatter plots, and complex tables. Success requires a three-step process: first, scan the titles and axes to understand the context; second, identify exactly which variables the question is asking for; and third, perform the calculation using the AI Exam Simulator or a standard calculator provided during the test. Understanding the scale of the axes and the units of measurement (e.g., thousands vs. millions) is critical to avoiding common pitfalls.

Solved Examples

The following examples demonstrate how to extract data and apply mathematical operations to reach a solution.

1. Example 1: Percentage Increase
   Scenario: A company's revenue was $400,000 in 2020 and $520,000 in 2021. What was the percentage increase in revenue?
   Solution:
   1. Identify the initial value ($V_1 = 400,000$) and final value ($V_2 = 520,000$).
   2. Use the percentage change formula: $$\text{Percent Change} = \frac{V_2 - V_1}{V_1} \times 100$$
   3. Substitute the values: $$\frac{520,000 - 400,000}{400,000} = \frac{120,000}{400,000}$$
   4. Simplify the fraction: $$\frac{12}{40} = 0.3$$
   5. Multiply by 100 to get 30%.
2. Example 2: Ratio from a Pie Chart
   Scenario: A city budget of $10 million is divided as follows: Education 40%, Public Safety 30%, Parks 10%, and Other 20%. What is the ratio of the amount spent on Education to the amount spent on Parks?
   Solution:
   1. Identify the percentages: Education = 40%, Parks = 10%.
   2. Since they share the same base ($10 million), you can compare the percentages directly.
   3. Set up the ratio: $40:10$.
   4. Simplify the ratio by dividing both sides by 10: $4:1$.
3. Example 3: Weighted Average from a Table
   Scenario: A class has two sections. Section A has 20 students with an average score of 80. Section B has 30 students with an average score of 90. What is the average score for the entire class?
   Solution:
   1. Calculate the total points for Section A: $$20 \times 80 = 1,600$$
   2. Calculate the total points for Section B: $$30 \times 90 = 2,700$$
   3. Find the sum of all points: $$1,600 + 2,700 = 4,300$$
   4. Find the total number of students: $$20 + 30 = 50$$
   5. Divide total points by total students: $$\frac{4,300}{50} = 86$$

Practice Questions

Use the following data for Questions 1-3: A technology firm employs 500 people. 60% are engineers, 20% are in sales, and the rest are in administration.

1. How many employees work in the administration department?

2. If the number of engineers increases by 10% next year, how many engineers will the firm have?

3. What is the ratio of engineers to sales staff?

Use the following data for Questions 4-6: Annual Rainfall in City X: Year 1: 40 inches, Year 2: 50 inches, Year 3: 35 inches, Year 4: 45 inches.

4. What is the average (arithmetic mean) annual rainfall over the four-year period?

5. What was the percentage decrease in rainfall from Year 2 to Year 3?

6. If Year 5 rainfall is expected to be 20% higher than the average of the first four years, what is the projected rainfall for Year 5?

Use the following data for Questions 7-8: A store sells three products. Product A sells for $15 (100 units sold), Product B for $25 (200 units sold), and Product C for $50 (50 units sold).

7. What is the total revenue generated from the sale of all three products?

8. Product B revenue accounts for approximately what percent of the total revenue?

Answers & Explanations

1. 100 employees. Administration accounts for $100\% - (60\% + 20\%) = 20\%$. Calculation: $0.20 \times 500 = 100$.
2. 330 engineers. Current engineers: $0.60 \times 500 = 300$. A 10% increase is $300 \times 1.10 = 330$.
3. 3:1. Percentage of engineers is 60%; percentage of sales is 20%. The ratio is $60:20$, which simplifies to $3:1$.
4. 42.5 inches. Sum of rainfall: $40 + 50 + 35 + 45 = 170$. Average: $\frac{170}{4} = 42.5$.
5. 30%. Decrease = $50 - 35 = 15$. Percentage decrease: $$\frac{15}{50} \times 100 = 30\%$$
6. 51 inches. The average is 42.5. A 20% increase: $42.5 \times 1.20 = 51$.
7. $9,000. Revenue A: $15 \times 100 = 1,500$. Revenue B: $25 \times 200 = 5,000$. Revenue C: $50 \times 50 = 2,500$. Total: $1,500 + 5,000 + 2,500 = 9,000$.
8. 55.6%. Revenue B is $5,000. Total revenue is $9,000. Calculation: $$\frac{5,000}{9,000} \approx 0.5555 \dots \text{ or } 55.6\%$$

1. If a bar chart shows that Company A's profit grew from $2 million to $2.5 million, what was the percent increase?

• A20%
• B25%
• C50%
• D12.5%

Frequently Asked Questions

What math concepts are tested in GRE Data Interpretation?

The GRE tests basic arithmetic, percentages, ratios, and elementary statistics like mean, median, and range. You will not need advanced calculus or trigonometry, but you must be comfortable with the quantitative reasoning logic used to extract these values from graphs.

How much time should I spend on each Data Interpretation set?

On average, you should allocate about 1.5 to 2 minutes per question. Since these questions come in sets of 2-4 based on one graph, spend the first 30 seconds carefully reading the graph's legend and axes to save time on subsequent calculations.

Can I use a calculator for these questions?

Yes, the GRE provides an on-screen calculator for the Quantitative Reasoning section. However, it is often faster to use estimation or mental math for simple percentage changes to avoid data entry errors.

What is the most common mistake made in Data Interpretation?

The most frequent error is misreading the units or scale on a graph's axis, such as confusing "millions of dollars" with "thousands of dollars." Test-takers also often solve for the wrong variable by not reading the question's specific constraints carefully.

How do I handle double-axis graphs?

When a graph has two different vertical axes, always check which data series corresponds to which axis by looking at the legend. Misaligning a data point with the wrong axis will lead to an incorrect value and a wrong final answer.