ECZ 2017 · O-Level Paper 1 — Sequences and Series
For the sequence 25, 22, 19, 16, …, find the formula for the nth term.
- A. 28 − 3n
- B. 25 − 3n
- C. 22 − 3n
- D. 3n − 28
Verified working — step 1
Substitute a and d into Tn = a + (n - 1)d, then expand with care: the -3 multiplies both n and -1.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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