Answer: n².
- A n²
- B n(n + 1)
- C n(n + 1)/2
- D 2n
Correct answer: A. n²
Explanation: The sum of the first n odd numbers is n²; e.g. 1 + 3 + 5 = 9 = 3².
Bar heights for AP 2, 5, 8, 11 with the common difference d=3 marked between consecutive terms.
Concept context
Arithmetic progressions, geometric progressions, and sums