Common DI Traps

Question

Common Data Insights Trap List:

Just starting this list. Not sure how long it will get but I have enough to get it going - my goal is to create a resource for Data Insights Traps that would help spot patterns of questions and make faster to go through DI with higher accuracy. Feel free to add yours and I will incorporate them into the first post/list but meanwhile, just recording things I am running into.

1. Splitting TPA question into 2 parts:
Example: https://gmatclub.com/forum/an-american- ... 82100.html See the spoiler below for more details

Show SpoilerQuestion Split Example

An American museum of East Asian art reviewed its acquisitions strategy in 2009. As part of that review, a marketing executive recommended purchasing more ceramics, jades, and paintings of people or landscapes because visitor surveys indicated that those types are of greatest interest to museumgoers in the region. The museum’s curator recommended purchasing more twenty-first-century East Asian art—particularly abstract (nonrepresentational) paintings and sculptures—because the museum’s collection is weakest in that area.

Among the East Asian works of art described below, select a painting and a sculpture, each of which satisfies at least one of the recommendations made by the marketing executive and at least one of the recommendations made by the curator. Make only two selections, one in each column.

Most people do not spot/register the part highlighted in yellow and end up spending way too much time on the question.

2. Forcing you to make way too many calculations
(there are probably numerous examples of this trap and further categorization would probably be needed)

A. Calculating instead of solving graphically. Here is an example of a question you can spend 4-6 minutes calculating by hand vs 2 minutes graphically.
https://gmatclub.com/forum/in-a-school- ... l#p3467407

B. Applying a different option of calculating / analyzing data. Here is an example of a question that you can solve in 2 minutes vs. 4 by changing how you calculate.
https://gmatclub.com/forum/the-table-be ... l#p3467020

C. Calculating instead of estimating and using the numerator/denominator relationship. E.g. if X/Y = Z, what happens if I increase X? will Z increase or decrease?
https://gmatclub.com/forum/the-graph-sh ... 27821.html

_________________

Founder of GMAT Club

Just starting out with GMAT? Start here with a Free 12-Week Study Plan

Signature Read More

kovid231 · Accepted Answer

Hey, I have been falling prey to these traps (in tables and majorly in question framing traps as well, so got some help to do a macro trend here. these are not the only ones, but these should help)

1. The “Base Change” Trap (Denominators)
Framing: “The price increased by 20% in January and then decreased by 20% in February.”
Trap: Assuming the price returns to the original value (Net 0% change).
Reality: The second percentage applies to a new base. Start with 100. Increase 20% → 120. Decrease 20% of 120 → 24. 120 − 24 = 96.
Gymnastics Key: Percentages are never additive when the base changes. Up x% and down x% always results in a net loss.

2. The “Nested Denominator” Trap (Table Analysis / MSR)
Framing: “Of the Exporting companies, what percentage are Tech firms?”
Trap: Using the grand total of all companies as the denominator.
Reality: “Of the  ” restricts the universe. If 500 total companies exist but only 100 are exporters, your denominator is 100.
Gymnastics Key: The noun immediately after “of” is your denominator.

3. The “Relative vs. Absolute” Growth Trap (Graphics)
Framing: Option A: “Product X is 120% of Product Y.” Option B: “Product X is 120% greater than Product Y.”
Trap: Treating them as the same.
Reality: 120% of Y → X = 1.2Y (20% increase). 120% greater than Y → X = 2.2Y (120% increase).
Gymnastics Key: “Greater than,” “more than,” or “increase” adds 100% to the percentage.

4. The “Max Decrease vs. Max Value” Trap (Extrema)
Framing: “Which year experienced the greatest decrease in revenue?”
Trap: Picking the year with the lowest value.
Reality: You want the largest negative change between consecutive years — not the lowest point.
Gymnastics Key: Greatest decrease = largest drop (change). Lowest value = smallest point.

5. The “Unit Synthesis” Conversion Trap (Two-Part Analysis)
Framing: “The machine produces 10 units per minute at a cost of $120 per hour.”
Trap: Dividing 120 by 10.
Reality: Units mismatch. 10 units/min = 600 units/hour. 120 ÷ 600 = $0.20 per unit.
Gymnastics Key: If time units don’t match, convert before calculating.

6. The “Only” Exception Trap (Data Sufficiency / Tables)
Framing: “Is Year X the only year in which exports exceeded imports?”
Trap: Checking Year X and stopping.
Reality: You must check every other year to ensure none also qualify.
Gymnastics Key: “Only” means search for one counterexample.

7. The “Inclusive vs. Exclusive” Range Trap
Framing: “Between June and October” vs. “From June through October”
Trap: Counting both as 5 months.
Reality: Between → exclusive (July, Aug, Sept = 3 months). From...through → inclusive (June–Oct = 5 months).
Gymnastics Key: Between = exclude endpoints. Through/To = include endpoints.

8. The “Not Less Than” Floor Trap
Framing: “Revenue was not less than 110% of the previous year.”
Trap: Looking for exactly 10% increase.
Reality: This means Revenue ≥ 110%. A 10%, 50%, or 200% increase all satisfy it.
Gymnastics Key: Not less than → ≥ Not more than → ≤ Translate immediately.

9. The “Weighted Average” Pull Trap
Framing: Group A: 1,000 people at 10% Group B: 10 people at 50%
Trap: (10% + 50%) ÷ 2 = 30%
Reality: Group A dominates. Actual combined rate ≈ 10.4%.
Gymnastics Key: If sample sizes differ, simple average is wrong. The result must be closer to the larger group.

10. The “Reverse Condition” Trap (MSR)
Framing: “If the project was over budget, then it was late.”
Trap: Checking all late projects.
Reality: Filter = over budget projects only.
Gymnastics Key: The phrase after “If” defines the filter.

11. The “Cumulative vs. Incremental” Trap (Graphics)
Framing: A line graph titled “Total Cumulative Sales.” Question: “In which month were sales highest?”
Trap: Choosing the highest point (December).
Reality: Cumulative graphs always rise. You need the steepest jump (largest month-to-month increase).
Gymnastics Key: If you see “Cumulative,” highest = steepest slope.

12. The “Dual Axis” Deception (Graphics)
Framing: Bars show Revenue. Line shows Growth %. Line appears visually higher.
Trap: Comparing heights directly.
Reality: They use different Y-axes.
Gymnastics Key: Always match the data point to its axis before comparing.

13. The “Correlation is Not Causation” Trap
Framing: Variable A increases. Variable B increases. Statement: “A caused B.”
Trap: Marking True because trends match.
Reality: Data shows correlation only.
Gymnastics Key: Unless a mechanism is explicitly stated, causation is not proven.

14. The “Projection vs. Fact” Trap
Framing: Email says: “We expect 50% increase.” Table shows 10% increase.
Trap: Treating projection as fact.
Reality: Expectation ≠ actual data.
Gymnastics Key: If question asks for fact, go to data tables — not opinion text.

15. The “Standardization” Trap
Framing: Store A: 500 units per day. Store B: 10,000 units per month.
Trap: Choosing 10,000 as larger.
Reality: Store A = 15,000 per month (500 × 30).
Gymnastics Key: Convert to same time unit before comparing.

16. The “Median vs. Mean” Outlier Trap
Framing: Salaries: 20k, 22k, 25k, 28k, 500k Statement: “Typical employee earns over 100k.”
Trap: Using mean (119k).
Reality: Median = 25k.
Gymnastics Key: If outlier exists and question says “typical,” use median.

17. The “Extrapolation” Trap
Framing: Graph shows upward trend 2020–2025. Statement: “Revenue in 2026 will be higher.”
Trap: Marking True due to trend.
Reality: No data for 2026.
Gymnastics Key: If it’s outside the chart range, it cannot be determined.

GmatTest2026 · Answer

Thank you for sharing the insights. It's helpful!

Thanks,
Pooja

bb · Answer

Mistake 3: Get Suckered into Calculations

Quite often, you can approximate the numbers and skip lengthy calculations. Even though the calculator is provided, and it is tempting to use it, often you can understand which answer will be correct since they are provided in the drop down.

https://gmatclub.com/forum/the-graph-sh ... 27821.html

This is considered a very hard question, but it can be answered quite quickly if you do quick math and then check the answer distribution to get a sense what options are available.

_________________

Founder of GMAT Club

Just starting out with GMAT? Start here with a Free 12-Week Study Plan

Signature Read More

oliviaren · Answer

This is extremely helpful. Thanks!

velitearum · Answer

Thanks, very helpful!

Common DI Traps

Prep Toolkit

Top 5 GMAT Debrief Videos

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia