The key concept being tested here is comparing two quantities using only indirect information through a third — one of the trickiest traps in Data Sufficiency.
Before touching the statements, translate the question using the pie charts:
- Finance: 33% are researchers → Researchers in Finance = 0.33F
- Economics: 61% are researchers → Researchers in Economics = 0.61E
- Mathematics: 44% are researchers → Researchers in Mathematics = 0.44M
The question asks: Is 0.44M > 0.33F?
Step 1 — Evaluate Statement 1: "More economics researchers than mathematics researchers" → 0.61E > 0.44M. This tells us Economics > Math, but says nothing about Finance. Insufficient.
Step 2 — Evaluate Statement 2: "More economics researchers than finance researchers" → 0.61E > 0.33F. This tells us Economics > Finance, but says nothing about Math. Insufficient.
Step 3 — Combine both statements: Now we know Economics is the largest. But do we know whether Math or Finance is second? No. Consider two scenarios:
- If M = 100, F = 200, E = 1000 → Math researchers = 44, Finance researchers = 66. Finance > Math. Answer: No.
- If M = 200, F = 100, E = 1000 → Math researchers = 88, Finance researchers = 33. Math > Finance. Answer: Yes.
Both scenarios satisfy both statements, but give opposite answers. Combined is still Insufficient.
Answer: E
Common trap: Students see that both statements involve the same third quantity (Economics) and assume the combination must pin down the relationship between Math and Finance. It doesn't — you still have no constraint on the relative sizes of the Math and Finance departments.
Takeaway: Whenever DS asks you to compare A and B but both statements only give you info about A vs C and B vs C, test numbers to check if A and B can swap positions while keeping C the largest.
— Kavya | 725 (GMAT Focus) | Founder @ edskore.com