Answer: 590.
- A 580
- B 590
- C 600
- D 610
Correct answer: B. 590
Explanation: a = 1, d = 3. S20 = 20/2 [2 + 19×3] = 10 × 59 = 590.
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