Question 17
Sequences and SeriesFind the sum of the first 30 terms of the sequence: −5, −3, −1, …
- A.640
- B.720
- C.750
- D.800
Show the answer and explanation
Answer: B (720)
Explanation
This is an A.P. with a = −5, d = 2. S₃₀ = 30/2 × [2(−5) + 29(2)] = 15 × 48 = 720.