SPM 2017 Add Maths Paper 2, Question 4Progressions

Solved on video in English and Bahasa Melayu · 7 marks · Form 4, Progressions · 6:09 video

The question

Diagram 2 shows part of a rectangular wall painted with red (R), blue (B) and yellow (Y) subsequently. The height of the wall is 2 m. The side length of the first coloured rectangle is 5 cm and the side length of each subsequent coloured rectangle increases by 3 cm. It is given that the total number of the coloured rectangles is 54. (a) Find (i) the side length, in cm, of the last coloured rectangle, (ii) the total length, in cm, of the painted wall. (b) Which coloured rectangle has an area of 28 000 cm²? Hence, state the colour of that particular rectangle.

[7 marks]

SPM 2017 Add Maths Paper 2, Question 4: the question as drawn in Eduly's video6:09

Step 1

Side lengths form an arithmetic progression: 5, 8, 11, ... with a = 5, d = 3

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

Final answer

(a)(i) 164 cm; (a)(ii) 4563 cm; (b) the 46th rectangle, Red

Where students lose marks

Watch out: use 200 cm, not 2, for the height in the area progression, and check the remainder of 46 ÷ 3.

Watch every step of this question solved on video (6:09), 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 2017 Paper 2

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.