MRSM Trial 2025 Add Maths Paper 2, Question 13Linear Programming

Solved on video in English · Form 5, Linear Programming · 6:20 video

The question

(a)

Roy's Collection is a clothing boutique that accepts orders for trousers and shirts. Table 2 shows the preparation and sewing time per item — Trousers: preparation 45 min, sewing 50 min; Shirt: preparation 30 min, sewing 70 min. The maximum preparation time is A hours and the sewing time is at least 5 hours 50 minutes. In a certain period the boutique prepares x trousers and y shirts, and the ratio of trousers to shirts successfully prepared does not exceed 4 : 5.

(a) The inequality involving the maximum preparation time A hours is represented by the straight line given on the graph paper. Find the value of A.

(b)

Roy's Collection (trousers: prep 45 min, sewing 50 min; shirt: prep 30 min, sewing 70 min; max preparation A = 10 hours; sewing at least 5 h 50 min; ratio trousers : shirts does not exceed 4 : 5; x trousers, y shirts).

(b) Write two inequalities other than the inequality in (a), x ≥ 0 and y ≥ 0, that satisfy all of the above constraints.

(c)

Roy's Collection, with constraints 45x + 30y ≤ 600, 50x + 70y ≥ 350, x/y ≤ 4/5, x ≥ 0, y ≥ 0.

(c) Construct and label the region R which satisfies all constraints.

(d)

Roy's Collection, region R as constructed. The price of a pair of trousers and a shirt is RM350 and RM200 respectively.

(d) It is given that the boutique successfully prepared x pairs of trousers and y shirts within 2 days. By using the objective function, determine whether the boutique is able to continue its operation if the monthly cost is RM40 000.

MRSM Trial 2025 Add Maths Paper 2, Question 13: the question as drawn in Eduly's video6:20

Part (a)

Step 1

The preparation-time constraint is 45x + 30y ≤ A × 60 (A hours in minutes). At x = 0 the boundary line gives 30y = 60A → y-intercept = 2A.

Why this step

The table times are in minutes but A is in hours, so we use A × 60. Forgetting this conversion is a common way to lose the mark.

1 more step, with the reason for it, in the full solution

Final answer

A = 10

Where students lose marks

Watch out: A is in hours but the table is in minutes, so use 60A, and read the y-intercept carefully from the graph.

Part (b)

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

Final answer

50x + 70y ≥ 350 and x/y ≤ 4/5

Where students lose marks

Watch out: 5 h 50 min is 350 minutes, not 550, and 'does not exceed 4 : 5' means x/y ≤ 4/5, not ≥.

Part (c)

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

Final answer

Region R shaded and labelled (see video)

Where students lose marks

Watch out: test each line to shade the correct side, and remember to label the region R.

Part (d)

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

Final answer

Yes, RM64 500 > RM40 000

Where students lose marks

Watch out: RM4300 is only for 2 days. Multiply by 15 before comparing with RM40 000, and test only points inside R.

Watch every step of this question solved on video (6:20), with the reason behind each step and a box that checks your own answer.

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

More Linear Programming questions

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