Target Exam

CUET

Subject

Section B2

Chapter

Linear Programming

Question:

A company manufactures two types of screws A and B. All the screws have to pass through a threading machine and a slotting machine. A box of Type A screws requires 2 minutes on the threading machine and 3 minutes on the slotting machine. A box of type B screws requires 8 minutes of threading on the threading machine and 2 minutes on the slotting machine. In a week, each machine is available for 60 hours. On selling these screws, the company gets a profit of Rs 100 per box on type A screws and Rs 170 per box on type B screws. Formulate this problem as a LPP given that the objective is to maximise profit.

Options:

Max $Z = 100x + 170y$ subject to $x + 4y \leq 1800, 3x + 2y \leq 3600, x, y \geq 0$

Max $Z = 170x + 100y$ subject to $x + 4y \leq 1800, 3x + 2y \leq 3600, x, y \geq 0$

Max $Z = 100x + 170y$ subject to $2x + 8y \geq 3600, 3x + 2y \geq 3600, x, y \geq 0$

Max $Z = 100x + 170y$ subject to $x + 4y \leq 3600, 3x + 2y \leq 3600, x, y \geq 0$

Correct Answer:

Max $Z = 100x + 170y$ subject to $x + 4y \leq 1800, 3x + 2y \leq 3600, x, y \geq 0$

Explanation:

The correct answer is Option (1) → Max $Z = 100x + 170y$ subject to $x + 4y \leq 1800, 3x + 2y \leq 3600, x, y \geq 0$

Let the company manufactures $x$ boxes of type A screws and $y$ boxes of type B screws.

From the given information, we can construct the following table.

Items

Type A (x)

Type B (y)

Minimum time available on each machine in a week

Time required on threading machine

2

8

$60 \times 60 = 3600$ minutes

Time required on slotting machine

3

2

$60 \times 60 = 3600$ minutes

Profit

₹100

₹170

As per the information in the above table, the objective function for maximum profit $Z = 100x + 170y$

Subject to the constraints

$2x + 8y \leq 3600$

$⇒x + 4y \leq 1800 \quad \dots(i)$

$3x + 2y \leq 3600 \quad \dots(ii)$

$x \geq 0, y \geq 0$ (non-negative constraints)

Hence, the required LPP is Maximise $Z = 100x + 170y$

Subject to the constraints,

$x + 4y \leq 1800, 3x + 2y \leq 3600, x \geq 0, y \geq 0$.