﻿   Solve the following LPP graphically: Maximize and Minimize   Z = 3x + 5y   Subject to   3x – 4y + 12 ≥ 0                        2x – y + 2 ≥ 0                     2x + 3y – 12 ≥ 0                                 0 ≤ x ≤ 4                                        y ≥ 2. : Kaysons Education

# Solve The Following LPP Graphically: Maximize And Minimize   Z = 3x + 5y   Subject To   3x – 4y + 12 ≥ 0                        2x – y + 2 ≥ 0                     2x + 3y – 12 ≥ 0                                 0 ≤ x ≤ 4                                        y ≥ 2.

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## Question

### Solution

Correct option is

Minimum value 19 at x = 3 and y = 2 & maximum value of Z is 42 at x = 4 and y = 6

The given LPP can be re-written as

Maximize or Minimize    Z = 3x + 5y

Subject to    3x – 4y  ≥ –12

2x – y  ≥ –2

2+ 3 ≥ 12

x ≤ 4

y ≥ 2

x ≥ 0

Converting the inequations into equations, we obtain the following equations 3x – 4y = –12, 2x – y = –2, 2x + 3y = 12, x = 4, y = 2 and x = 0.

These lines are drawn on suitable scale. The shaded region P1P2P3P4P5shown in fig. represents the feasible region of the given LPP.

The values of the objective function at these points are given in the following table:

 Point (x, y) Values of the objective function                  Z = 3x + 5y P1(3, 2) P2(4, 2)   P3(4, 6) Z = 3 × 3 + 5 × 2 = 19   Z = 3 × 4 + 2 × 5 = 22 Z = 3 × 4 + 5 × 6 = 42

Clearly Z assume its minimum value 19 at x = 3 and y = 2. The maximum value of Z is 42 at x = 4 and y = 6.

#### SIMILAR QUESTIONS

Q1

A diet is to contain at least 400 units of carbohydrate, 500 units of fat, and 300 units of protein. Two foods are available: F1 which costs Rs 2 per unit, and F2 which costs Rs 4 per unit. A unit of food F1 contains 10 units of carbohydrate, 20 units of fat, and 15 units of protein; a unit of food F2 contains 25 units of carbohydrate, 10 units of fat, and 20 unit of protein. Find the minimum cost for a diet consists of a mixture of these two foods and also meets the minimum nutrition requirements. Formulate the problem as a linear programming problem.

Q2

The objective of a diet problem is to ascertain the quantities of certain foods that should be eaten to meet certain nutritional requirement at minimum cost. The consideration is limited to milk, beaf and eggs, and to vitamins ABC. The number of milligrams of each of these vitamins contained within a unit of each food is given below:

 Vitamin Litre of milk Kg of beaf Dozen of eggs Minimum daily requirements A B C 1 100 10 1 10 100 10 10 10 1 mg 50 mg 10 mg Cost Rs 1.00 Rs 1.10 Re 0.50

What is the linear programming formulation for this problem?

Q3

There is a factory located at each of the two places P and Q. From these locations, a certain commodity is delivered to each of the three depots situated at AB and C. The weekly requirements of the depots are respectively 5, 5 and 4 units of the commodity while the production capacity of the factories at P and Q are 8 and 6 units respectively. The cost of transportation per unit is given below.

 To From Cost (in Rs) A B C P Q 16 10 10 12 15 10

How many units should be transported from each factory to each in order that the transportation cost is minimum. Formulate the above as a linear programming problem.

Q4

A brick manufacturer has two depots, A and B, with stocks of 30,000 and 20,000 bricks respectively. He receives orders from three builders PQand R for 15,000, 20,000 and 15,000 bricks respectively. The cost in Rs of transporting 1000 bricks to the builders from the depots are given below:

 From To P Q R A B 40 20 20 60 30 40

How should the manufacturer fulfil the orders so as to keep the cost of transportation minimum?

Formulate the above linear programming problem.

Q5

A company is making two products A and B. The cost of producing one unit of products A and B are Rs 60 and Rs 80 respectively. As per the agreement, the company has to supply at least 200 units of product B to its regular customers. One unit product A requires one machine hour whereas product B has machine hours available abundantly within the company. Total machine hours available for product A are 400 hours. One unit of each product A and B requires one labour hour each and total of 500 labour hours are available. The company wants to minimize the cost of production by satisfying the given requirements. Formulate the problem as a LLP.

Q6

A firm manufactures two products, each of which must be processed through two departments, 1 and 2. The hourly requirements per unit for each product in each department, the weekly capacities in each department, selling price per unit, labour cost per unit, and raw material cost per unit are summarized as follows:

 Product A Product B Weekly capacity Department 1 3 2 130 Department 2 4 6 260 Selling price per unit Rs 25 Rs 30 Labour cost per unit Rs 16 Rs 20 Raw material cost per unit Rs 4 Rs 4

The problem is to determine the number of units of produce each product so as to maximize total contribution to profit. Formulate this as a LLP.

Q7

Solve the following LPP graphically:

Maximize    Z  = 5x + 3y

Subject to

3x + 5y ≤ 15

5x + 2y ≤ 10

And,    xy ≥ 0.

Q8

Solve the following LPP by graphical method:

Minimize    Z = 20x + 10y

Subject to   x + 2y ≤ 40

3x + y ≥ 30

4x + 3y ≥ 60

And,           xy ≥ 0

Q9

Solve the following LPP graphically:

Minimize and Maximize Z = 5x + 2y

Subject to –2x – 3y ≤ – 6

x – 2y ≤ 2

3x + 2y ≤ 12

–3x + 2y ≤ 3

xy ≥ 0

Q10

Solve the following linear programming problem graphically:

Maximize  Z = 50x + 15y

Subject to

5x + y ≤ 100

x + y ≤ 60

xy ≥ 0.