Answer: n(n+1)(2n+1)/6.
- A n(n+1)/2
- B n(n+1)(n+2)/6
- C n(n+1)(2n+1)/6
- D n²(n+1)/2
Correct answer: C. n(n+1)(2n+1)/6
Explanation: Sum of squares = n(n+1)(2n+1)/6. For n=3: 3×4×7/6 = 14.
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