ECZ 2016 · O-Level Paper 1 — Sequences and Series
The first and second terms of an arithmetic progression are 100 and 95, respectively. Find the sum of the first ten terms. [Sn = n2(2a + (n − 1)d)]
- A. 700
- B. 550
- C. 775
- D. 1000
Verified working — step 1
The sum formula is handed to you - substitute a, d and n, then finish the bracket before multiplying.The full step-by-step working and final answer, plus the video lesson for this topic, are included with Premium — checked against ECZ marking standards.
Original examination question © Examinations Council of Zambia. Worked solution and commentary © G12 Titan — not to be reproduced without permission.
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