Key concept: Properties of Average and Median for Consecutive Integer Sequences
This is a great Data Sufficiency question because both statements look similar on the surface but force you to think through the same underlying property twice — from slightly different angles.
One key fact to anchor on: For consecutive integers from 1 to m, both the average and the median equal (1 + m) / 2. This is the same formula — because consecutive integers are symmetric around their middle value.
Evaluate Statement (1): "The average is not an integer."
Average = (1 + m) / 2. For this NOT to be an integer, (1 + m) must be odd, which means m must be even. If m is even, then m ≠ 49 (since 49 is odd). We get a definitive "NO" to the question — SUFFICIENT.
Evaluate Statement (2): "The median is not an integer."
For consecutive integers 1 through m, the median is also (1 + m) / 2. Same logic: not an integer → m is even → m ≠ 49. Again a definitive "NO" — SUFFICIENT.
Answer: (D) — each statement alone is sufficient.
Common trap: Students sometimes worry that a "NO" answer isn't really sufficient — they think sufficiency only applies when the answer is "YES." That's wrong. In Data Sufficiency, a clear and definitive "NO" is just as sufficient as a clear "YES." The question is whether you can answer the yes/no question, not whether the answer happens to be yes.
A second trap: seeing that both statements give the same result and assuming you must be making an error. You're not — it just means the GMAT designed the question so (D) is the answer.
Takeaway: In DS problems involving sequences or sets, immediately write down the formula for average and median — they're often the key that unlocks both statements at once.
— Kavya | 725 (99th percentile), GMAT Focus Edition