GMAT Focus EditionData InsightsMedium
A production manager is reviewing the output data for two manufacturing lines, Line A and Line B, over the past quarter. The data includes the total units produced and the number of defective units. **Statement 1:** Line A produced 15,000 units with 450 defective units. Line B produced 18,000 units with 630 defective units. **Statement 2:** The defect rate for Line A was 3%, and the defect rate for Line B was 3.5%. Is the defect rate of Line A less than that of Line B?
- ABoth statements together are sufficient, but neither statement alone is sufficient.
- BStatement 1 alone is sufficient, but statement 2 alone is not sufficient.
- CStatement 2 alone is sufficient, but statement 1 alone is not sufficient.
- DEach statement alone is sufficient.
Show answer & explanationAnswer & explanation
Correct answer: D. Each statement alone is sufficient.
Statement 1 allows calculation of defect rates for both lines, enabling a comparison. Statement 2 directly provides the defect rates, also enabling a comparison. Therefore, each statement alone is sufficient.
Why the other options are wrong
- A. Both statements are individually sufficient, so they are not needed together. This option is incorrect.
- B. Statement 1 alone is sufficient. Defect rate for Line A = 450/15000 = 0.03 = 3%. Defect rate for Line B = 630/18000 = 0.035 = 3.5%. We can compare them. This option incorrectly states statement 2 is not sufficient.
- C. Statement 2 alone is sufficient as it directly provides the rates (3% vs 3.5%). This option incorrectly states statement 1 is not sufficient.
Data Sufficiency: Rate Comparison
Data Sufficiency questions ask whether the provided statements offer enough information to answer a specific question, often involving comparing rates or ratios.
- Focus on sufficiency, not on actually solving the problem.
- Evaluate each statement independently first, then together if needed.
- A statement is sufficient if it unequivocally answers the question (yes or no).
Memory trick: Is it enough? That's the only question. Don't solve, just verify sufficiency.