Linear Programming

IMPORTANT

Linear Programming: Overview

This Topic covers sub-topics such as Linear Programming, Optimisation Problem, Manufacturing Problems, Graphical Method of Solving Linear Programming Problems and, Objective Function of a Linear Programming Problem

Important Questions on Linear Programming

MEDIUM
IMPORTANT

State the limitations of L.P.P.

MEDIUM
IMPORTANT

Define L.P.P and its advantages.

MEDIUM
IMPORTANT

A candle plant manufactures two types of products X and Y and sells them at a profit of 5 on type X and 3 on type Y. Each product is processed on two machines G and H. Type X requires one minute of processing time on G and two minutes on H; type Y requires one minute on G and one minute on H. The machine G is available for not more than 6 hours 40 minutes, while machine H is available for 8 hours 20 minutes during any working day; formulate the problem as linear programming problem.

EASY
IMPORTANT

Define unbounded feasible region in linear programming.

EASY
IMPORTANT

The bounded feasible region for a linear programming problem (LPP) is given as below:

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Which one of the following can be optimal solution for the given LPP.

EASY
IMPORTANT

Which one of the following is infeasible solution to the linear programming problem (LPP), whose feasible region is given by:

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EASY
IMPORTANT

The linear inequalities or equations or restrictions on the variables of a linear programming problem (L.P.P.) are called:

HARD
IMPORTANT

A manufacturing company makes two types of teaching aids M and N of mathematics for class XII. Each type of M requires 9 labour hours of fabricating and 1 labour hour for finishing. Each type of N requires 12 labour hour for fabricating and 3 labour hour for finishing. For fabricating and finishing, the maximum labour hours available per week are 180 and 30 respectively. The company makes a profit of 80 on each piece of type M and 120 on each piece of type N. How many pieces of type M and type N should be manufactured per week to get a maximum profit? Make it as an LPP and solve graphically. What is the maximum profit per week?

HARD
IMPORTANT

A company manufactures two types of toys, a and b. Type a requires 5 minutes each for cutting and 10 minutes each for assembling. Type b required 8 minutes each for cutting and 8 minutes each for assembling. There are 3 hours available for cutting and 4 hours available for assembling in a day. The profit is 50 each on type a and 60 each on type b. how many toys of each types should the company manufactures in a day to maximise the profit?

HARD
IMPORTANT

Anil wants to invest at the most 12000 in bonds M and N. According to rules, he has to invest at least 2000 in bond M and at least 4000 in bond N. if the rate of interest of bond M is 8% per annum and on bond N, it is 10% per annum, how should he invest his money for maximum interest? Solve the problem graphically.

HARD
IMPORTANT

A manufacturer produces two types of steel trunks. He has two machines, M1 and M2. The first type of trunk requires 3 hours on machine M1 and 3 hours on machine M2. The second type required 3 hours on machine M1 and 2 hours on Machine M2. Machine M1 and M2 can work at most for 18 hours and 15 hours per day respectively. He earns a profit of 30 and 25 per trunk of the first type and second type respectively. How many trunks of each type must he make each day to make the maximum profit?

HARD
IMPORTANT

A firm manufactures two types of product, a and b, and sells them at a profit of 5 per unit of type a and 3 per unit of type b. Each product is processed on two machines, M1 and M2. One unit of type a requires one minute of processing time on M1 and two minutes of processing time on M2, whereas one unit of type b requires one minute of processing time on M1 and one minute on M2. Machines M1 and M2 are respectively available for at most 5 hours and 6 hours in a day. Find out how many units of each type of product the firm should produce a day in order to maximise the profit. Solve the problem graphically.

HARD
IMPORTANT

An oil company has two depots, a and b, with capacities of 7000 L and 4000 L respectively. The company is to supply oil to three pumps, d,e,f, whose requirements are 4500 L, 3000 L, and 3500 L respectively. The distances (in km) between the depots and the petrol pumps are given in the following table:

  Distance in km  

From 

To

a b
d 7 3
e 6 4
f 3 2

Assuming that the transportation cost per km is 1 rupee per litre, how should the delivery be scheduled in order that the transportation cost is minimum?

HARD
IMPORTANT

A medicine company has factories at two places, X and Y. From these places, supply is made to each of its three agencies situated at P, Q and R. the monthly requirement of the agencies are respectively 40 packets, 40 packets and 50 packets of medicine, while the production capacity of the factories at X and Y are 60 packets and 70 packets respectively. The transportation costs per packet from the factories to the agencies are given as follows.

  Transportation cost per packet (in )

From 

To

X Y
P 5 4
Q 4 2
R 3 5

How many packets from each factory should be transported to each agency so that the cost of transportation is minimum? Also, find the minimum cost.

HARD
IMPORTANT

A brick manufacturer has two depots, P and Q, with stocks of 30000 and 20000 bricks respectively. He receives order from three building a,b,c for 15000,20000 and 15000 bricks respectively. The costs of transporting 1000 bricks to the building from the depots are given below.

  Cost of transportation (in  per quintal)

From 

To

a b c
P 40 20 30
Q 20 60 40

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

HARD
IMPORTANT

A manufacturer makes two product, A and B. product A sells at 200 each and takes 12hour to make. Product B sells at 300 each and takes 1 hour to make. There is a permanent order for 14 of product A and 16 of product B. A working week consist of 40 hours of production and the weekly turnover must not be less than 10000. If the profit on each of the product A is 20 and on product B, it is 30 then how many of each should be produced so that the profit is maximum? Also, find the maximum profit.

HARD
IMPORTANT

A manufacturer makes two types, A and B, of teapots. Three machines are needed for the manufacture and the time required for each teapot on the machines is given below.

Each machine is available for a maximum of 6 hours per day. If the profit on each teapot of type A is 75 paise and that on each teapot of type B is 50 paise, show that 15 teapots of type A and 30 of type B should be manufactured in a day to get the maximum profit.   

Machine Time (in minutes)    
Type I II III
A 12 18 6
B 6 0 9

    

HARD
IMPORTANT

A manufacturer of a line of patent medicines is preparing a production plan on medicines A and B. There are sufficient ingredients available to make 20000 bottles of A and 40000 bottles of B but there are only 45000 bottles into which either of the medicines can be put. Furthermore, it takes 3 hours to prepare enough material to fill 1000 bottles of A and it takes 1 hour to prepare enough material to fill 1000 bottles of B, and there are 66 hours available for this operation. The profit is 8 per bottle for A and 7 per bottle for B. How should the manufacture schedule the production in order to maximize his profit? Also, find the maximum profit.

HARD
IMPORTANT

A dealer wishes to purchase a number of fans and sewing machines. He has only 5760 to invest and space for at most 20 items. A fan costs him 360 and a sewing machine,240. He expects to gain 22 on a fan and 18 on a sewing machine. Assuming that he can sell all the items he can buy, how should he invest the money in order to maximise the profit?

HARD
IMPORTANT

Mr. Dass wants to invest 12000 in public provident fund (PPF) and in national bonds. He has to invest at least 1000 in PPF and at least 2000 in bonds. If the rate of interest on PPF is 12% per annum and that on bonds is 15% per annum, how should he invest the money to earn maximum annual income? Also find the maximum annual income.