How many integers satisfy ?
Answer and explanation
Correct answer: A.
- Step 1: For the sum is , so every such works.
- Step 2: For : gives . For : gives .
- Step 3: The solution set is , whose integers are : that is integers.
Answer
.
Why not the others: would result from taking the lower limit as (at the sum is , so it fails); forgets one endpoint; and include values such as (sum ) and (sum ) which fail.
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