ECZ 2020 · O-Level Paper 1 — Sequences and Series

For the sequence 7, 11, 15, 19, ..., find the sum of the first 16 terms.

  • A. 592
  • B. 616
  • C. 1184
  • D. 296

Verified working — step 1

Adding sixteen terms one by one would work, but the sum formula is faster: Sn = n2(2a + (n - 1)d).

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Original examination question © Examinations Council of Zambia. Worked solution and commentary © G12 Titan — not to be reproduced without permission.

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