ECZ 2017 · O-Level Paper 2 · Question 5 — Sequences and Series

Question from ECZ 2017 · O-Level Paper 2 · Question 5

(a) For the geometric progression 20, 5, 1 14, ..., find

(a(i)) the common ratio,[2]

Verified working — step 1

The common ratio is any term divided by the one before it.

(a(ii)) the nth term,[2]

Verified working — step 1

The nth term of a GP is a rn-1, with a = 20 and r = …

(a(iii)) the sum of the first 8 terms.[3]

Verified working — step 1

Sn = a1 - rn1 - r with a = 20, r = 14, n = 8.

(b) Simplify 14x39y2 ÷ 7x418y3.[2]

Verified working — step 1

Dividing by a fraction means multiplying by its reciprocal.

The full step-by-step working and final answer 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

More Sequences and Series questions from past papers