ECZ 2021 · O-Level Paper 1 — Sequences and Series
The third and fourth terms of an Arithmetic progression are 6 and 3 respectively. Find the (b) formula for the nth term.
- A. 12 - 3n
- B. 15 - 3n
- C. 12 + 3n
- D. 15 + 3n
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.
Have a different question?
Search it — if it is from a past paper or a school mock, chances are we have it worked out, or one that uses the same method.
Search any past-paper question