SPM 2020 Add Maths Paper 1, Question 9Progressions

Solved on video in English and Bahasa Melayu · 3 marks · Form 4, Progressions · 3:26 video

The question

A circle is divided into n sectors so that the angles of the sectors form an arithmetic progression. Given the angle of the smallest sector is 3 degrees and the angle of the largest sector is 27 degrees, find the value of n.

[3 marks]

SPM 2020 Add Maths Paper 1, Question 9: the question as drawn in Eduly's video3:26

Step 1

The sector angles form an AP with first term a = 3 degrees and last term l = 27 degrees.

4 more steps, each with the reason for it, in the full solution

Final answer

n = 24

Where students lose marks

Watch out: T_n = a + (n − 1)d alone has two unknowns. Use S_n = (n/2)(a + l) = 360 to find n directly.

Watch every step of this question solved on video (3:26), with the reason behind each step and a box that checks your own answer.

Start 7 days freeAlready a member? Watch it now

No card. Every past-year question on video, in English and BM.

All questions in SPM 2020 Paper 1

Progressions: lessons and every past-year question

Baca dalam Bahasa Melayu

More Progressions questions

Questions are re-typeset by Eduly for study and commentary. Eduly is not affiliated with Lembaga Peperiksaan Malaysia or the Ministry of Education.