Answer: n/(n+1).
- A 1
- B 1 - 1/(n+1)
- C 1/(n+1)
- D n/(n+1)
Correct answer: D. n/(n+1)
Explanation: Telescoping: terms cancel in pairs. (1−½)+(½−⅓)+…+(1/n−1/(n+1)) = 1 − 1/(n+1) = n/(n+1). All middle terms vanish.
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