The 0-1-Negative Test

Quantitative Comparison + variables + the constraints don't uniquely determine the values.

Testing only 'normal' positive integers (2, 3, 5) and concluding A or B prematurely. The GRE designs traps that work for normal numbers but break for weird ones.

1. Try a normal value first (like 2). Note the relationship between the quantities.
2. Now try a 'weird' value, in this priority order: 0, then 1, then a negative number, then a fraction between 0 and 1.
3. If you get two different relationships → answer is D (cannot be determined).
4. If they stay consistent across all weird cases → likely A, B, or C. Try one more weird case to confirm.
5. Be especially suspicious when the constraint doesn't say 'positive' or 'integer.'

About a third of GRE Quant is QC, and D is both the most under-picked AND over-picked answer. This is your safety net pattern.