Answer: n²(n+1)²/4.
- A n(n+1)(2n+1)/6
- B n²(n+1)²/4
- C n(n+1)/2
- D n(2n+1)/3
Correct answer: B. n²(n+1)²/4
Explanation: Sum of cubes = [n(n+1)/2]² = n²(n+1)²/4.
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