An archaeologist studying Artifacts A–D is interested in whether Artifact C is older than Artifact A.
GMAT Two Part Analysis : (TPA) Questions
An archaeologist studying Artifacts A–D is interested in whether Artifact C is older than Artifact A.
Select an assertion involving Artifact A and an assertion involving Artifact C that together imply the assertion "Artifact C is older than Artifact A." Make only two selections, one in each column.
Phase 1: Owning the Dataset
Argument Analysis Table
Passage Statement | Analysis & Implications |
"An archaeologist studying Artifacts A–D" |
|
"is interested in whether Artifact C is older than Artifact A" |
|
Key Patterns Identified
- We have a finite set of 4 artifacts (A, B, C, D)
- We need to establish relative age relationships
- The goal is to prove C is older than A
- We can use transitive properties (if X > Y and Y > Z, then X > Z)
Phase 2: Question Analysis & Prethinking
Understanding Each Part
- Part 1 Focus: We need an assertion about Artifact A's age relative to another artifact
- Part 2 Focus: We need an assertion about Artifact C's age relative to another artifact
- Relationship: These two assertions must combine to prove \(\mathrm{C > A}\)
Valid Inference Generation
To prove \(\mathrm{C > A}\), we can:
- Direct comparison: Not available in our answer choices
- Indirect proof through B: If \(\mathrm{C > B}\) and \(\mathrm{B > A}\), then \(\mathrm{C > A}\)
- Indirect proof through D: If \(\mathrm{C > D}\) and \(\mathrm{D > A}\), then \(\mathrm{C > A}\)
Phase 3: Answer Choice Evaluation
Column 1 Options (Assertions involving Artifact A):
Option 1: "Artifact A is older than Artifact B" (\(\mathrm{A > B}\))
- What it claims: A predates B chronologically
- For our goal: If \(\mathrm{A > B}\), and we know something about C and B, this might not help prove \(\mathrm{C > A}\)
Option 2: "Artifact A is older than Artifact D" (\(\mathrm{A > D}\))
- What it claims: A predates D chronologically
- For our goal: Combined with \(\mathrm{C > D}\) wouldn't prove \(\mathrm{C > A}\)
Option 3: "Artifact B is older than Artifact A" (\(\mathrm{B > A}\))
- What it claims: B predates A chronologically
- For our goal: If \(\mathrm{B > A}\), and we can show \(\mathrm{C > B}\), then \(\mathrm{C > A}\) ✓
Column 2 Options (Assertions involving Artifact C):
Option 5: "Artifact C is older than Artifact D" (\(\mathrm{C > D}\))
- What it claims: C predates D chronologically
- For our goal: Would need \(\mathrm{D > A}\) from Column 1, which isn't available
Option 6: "Artifact C is older than Artifact B" (\(\mathrm{C > B}\))
- What it claims: C predates B chronologically
- For our goal: Combined with \(\mathrm{B > A}\) would prove \(\mathrm{C > A}\) ✓
Answer Selection Process
- Part 1 Selection: "Artifact B is older than Artifact A" - This gives us \(\mathrm{B > A}\)
- Part 2 Selection: "Artifact C is older than Artifact B" - This gives us \(\mathrm{C > B}\)
- Verification: \(\mathrm{C > B}\) and \(\mathrm{B > A}\) → \(\mathrm{C > A}\) ✓
The transitive property confirms our goal: Since C is older than B, and B is older than A, then C must be older than A.
Common Traps Avoided
- We didn't assume relationships not stated in our selected assertions
- We relied only on logical transitivity, not speculation
- Each assertion is meaningful on its own and together they form a complete proof