ECZ 2017 · O-Level Paper 2 · Question 11 — Linear Programming

Himakwebo orders maize and groundnuts for sale. The order price of a bag of maize is K75.00 and that of a bag of groundnuts is K150.00. He is prepared to spend up to K7 500.00 altogether. He intends to order at least 5 bags of maize and at least 10 bags of groundnuts. He does not want to order more than 70 bags altogether. Let x and y be the number of bags of maize and groundnuts respectively.

(a) If x and y are the number of bags of maize and groundnuts respectively, write four inequalities which represent these conditions.[4]

Verified working — step 1

Cost: 75x + 150y <= 7500, which simplifies to x + 2y <= 100.

(b) Using a scale of 2 cm to represent 10 bags on each axis, draw the x and y axes for 0 <= x <= 70 and 0 <= y <= 70 respectively and shade the unwanted region to show clearly the region where the solution of the inequalities lie.[4]

Verified working — step 1

Shade above x + 2y = 100, left of x = 5, below y = 10 and above x + y = …

(c) Given that the profit on a bag of maize is K25.00 and on a bag of groundnuts is K50.00, how many bags of each type should he order to have maximum profit?[2]

Verified working — step 1

Profit P = 25x + 50y, tested at the vertices:

(d) What is this estimate of the maximum profit?[2]

Verified working — step 1

P = 25(40) + 50(30) = 1000 + 1500 = …

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 Linear Programming questions from past papers