Each of the species of a certain type of insect has at least one of five significant traits: A, B,...
GMAT Two Part Analysis : (TPA) Questions
Each of the species of a certain type of insect has at least one of five significant traits: A, B, C, D, and E. Furthermore, one study has determined that any species with Trait A has at least one of the Traits B and C. Another study has determined that any species with Trait C has at least one of the Traits D and E. And a third study has determined that any of the species with Trait B has Trait C. The results of each study are correct.
In addition to the relationship between Traits B and C that is stated explicitly with respect to the third study, the passage implies that any of the insects that has Trait X also has Trait Y. Select different options for X and for Y such that the following statement most accurately describes the passage.
Phase 1: Owning the Dataset
Argument Analysis Table
| Passage Statement | Analysis & Implications |
| "Each species has at least one of five traits: A, B, C, D, and E" |
|
| "Any species with Trait A has at least one of Traits B and C" |
|
| "Any species with Trait C has at least one of Traits D and E" |
|
| "Any species with Trait B has Trait C" |
|
Key Patterns Identified
- Established Facts: Three conditional relationships (\(\mathrm{A} \rightarrow \mathrm{B}/\mathrm{C}\), \(\mathrm{C} \rightarrow \mathrm{D}/\mathrm{E}\), \(\mathrm{B} \rightarrow \mathrm{C}\))
- Chain Reactions: B creates a chain (\(\mathrm{B} \rightarrow \mathrm{C} \rightarrow \mathrm{D}/\mathrm{E}\))
- Important Limitation: We only know what traits lead to other traits, not what traits are led to
Phase 2: Question Analysis & Prethinking
Understanding the Two Parts
- Part 1 (X): We need a trait that implies another trait
- Part 2 (Y): We need the trait that is implied by X
- Relationship: \(\mathrm{X} \rightarrow \mathrm{Y}\) must be a valid inference from the passage (beyond \(\mathrm{B} \rightarrow \mathrm{C}\))
Generating Valid Inferences
Let's trace through the logical chains:
- If a species has A:
- It must have (B or C)
- If it has B, then \(\mathrm{B} \rightarrow \mathrm{C}\) means it has C
- If it has C, it already has C
- Therefore: \(\mathrm{A} \rightarrow \mathrm{C}\) (This is our key inference!)
- If a species has B:
- It must have C (given)
- Since \(\mathrm{C} \rightarrow (\mathrm{D} \text{ or } \mathrm{E})\), it must have D or E
- But we can't specify which one
- If a species has C:
- It must have (D or E)
- But we can't be more specific
Phase 3: Answer Choice Evaluation
We need to find X and Y where \(\mathrm{X} \rightarrow \mathrm{Y}\) is implied by the passage.
Evaluating Potential Relationships:
\(\mathrm{A} \rightarrow \mathrm{B}\)? No, \(\mathrm{A} \rightarrow (\mathrm{B} \text{ or } \mathrm{C})\), not necessarily B
\(\mathrm{A} \rightarrow \mathrm{C}\)? Yes! Whether A leads to B or C, we always get C
\(\mathrm{A} \rightarrow \mathrm{D}\)? No, \(\mathrm{A} \rightarrow \mathrm{C} \rightarrow (\mathrm{D} \text{ or } \mathrm{E})\), could be E instead
\(\mathrm{A} \rightarrow \mathrm{E}\)? No, same reasoning as above
\(\mathrm{B} \rightarrow \mathrm{D}\)? No, \(\mathrm{B} \rightarrow \mathrm{C} \rightarrow (\mathrm{D} \text{ or } \mathrm{E})\), could be E instead
\(\mathrm{B} \rightarrow \mathrm{E}\)? No, same reasoning as above
\(\mathrm{C} \rightarrow \mathrm{A}\)? No, nothing implies A must exist
\(\mathrm{D} \rightarrow \text{anything}\)? No implications given about D
\(\mathrm{E} \rightarrow \text{anything}\)? No implications given about E
Answer Selection
Part 1 (X): A - This trait creates an implied relationship
Part 2 (Y): C - This is the trait that must follow from A
Verification
Let's confirm \(\mathrm{A} \rightarrow \mathrm{C}\):
- Given: \(\mathrm{A} \rightarrow (\mathrm{B} \text{ or } \mathrm{C})\)
- Given: \(\mathrm{B} \rightarrow \mathrm{C}\)
- If A leads to B, then B leads to C ✓
- If A leads to C, then we have C ✓
- Therefore, A always leads to C ✓
This is the only additional guaranteed relationship we can derive from the given facts.