All Exams  >   Commerce  >   Applied Mathematics for Class 12  >   All Questions

All questions of Linear Programming for Commerce Exam

Objective function of a LPP is​
  • a)
    function to be optimized
  • b)
    A constraint
  • c)
    Relation between variables
  • d)
    Equation in a line
Correct answer is option 'A'. Can you explain this answer?

Jaideep Basu answered
Objective function of a Linear Programming Problem (LPP)

The objective function of a Linear Programming Problem (LPP) is a mathematical function that is to be optimized or maximized. It represents the goal or objective of the problem and determines the best possible solution.

Understanding Linear Programming

Linear Programming is a mathematical technique used to determine the best possible outcome or solution in a given set of constraints. It involves optimizing a linear objective function while adhering to a set of linear constraints.

The Components of a LPP

A Linear Programming Problem consists of the following components:

1. Decision Variables: These are the variables that represent the quantities or values that we want to determine or find. They are denoted by x1, x2, x3, etc.

2. Objective Function: The objective function is a mathematical expression that defines the goal or objective of the problem. It is a linear combination of the decision variables and is either to be maximized or minimized.

3. Constraints: Constraints are the limitations or restrictions that need to be satisfied while finding the optimal solution. They are represented by a set of linear inequalities or equations.

4. Feasible Region: The feasible region is the set of all possible solutions that satisfy the given constraints.

The Objective Function

The objective function is a key component of a Linear Programming Problem. It quantifies the objective or goal in terms of the decision variables and defines the direction of optimization. The objective can be to maximize profits, minimize costs, maximize production, minimize waste, etc.

The objective function is typically a linear equation or expression that involves the decision variables. It may have coefficients that represent the importance or weightage of each decision variable in achieving the objective. The coefficients can be positive or negative depending on whether the objective is to be maximized or minimized.

Conclusion

In summary, the objective function of a Linear Programming Problem (LPP) represents the goal or objective that needs to be optimized or maximized. It is a mathematical expression involving the decision variables and determines the direction of optimization. The objective function plays a crucial role in finding the optimal solution within the given constraints.

In linear programming problems the optimum solution
  • a)
    satisfies a set of piecewise – linear inequalities (called constraints)
  • b)
    satisfies a set of linear inequalities (called linear constraints)
  • c)
    satisfies a set of quadratic inequalities (calledconstraints)
  • d)
    satisfies a set of cubic inequalities (calledconstraints)
Correct answer is option 'B'. Can you explain this answer?

Explanation:

Linear Programming Problems:
Linear programming involves optimizing a linear objective function subject to a set of linear constraints. The goal is to find the values of the decision variables that maximize or minimize the objective function while satisfying all constraints.

Optimum Solution:
The optimum solution in linear programming problems refers to the values of the decision variables that result in the maximum or minimum value of the objective function while still meeting all the constraints.

Linear Inequalities:
In linear programming, the constraints are typically represented as linear inequalities. These are mathematical statements that involve linear expressions (variables raised to the power of 1) connected by inequality symbols such as ≤, ≥, or =.

Optimum Solution and Linear Inequalities:
The optimum solution in linear programming satisfies a set of linear inequalities, also known as linear constraints. These constraints define the feasible region within which the optimal solution must lie. The optimal solution is the point within this feasible region that maximizes or minimizes the objective function.

Conclusion:
Therefore, in linear programming problems, the optimum solution always satisfies a set of linear inequalities or linear constraints. This is a fundamental aspect of linear programming and is crucial for finding the most efficient solutions to optimization problems.

The optimum value of the objective function is attained at the points​
  • a)
    Corner points of feasible region
  • b)
    Any point of the feasible region
  • c)
    On x-axis
  • d)
    On y-axis
Correct answer is option 'A'. Can you explain this answer?

Anjali Reddy answered
Given that,

• There is an objective function

• There are optimal values

From the definition of optimal value of a Linear Programming Problem(LPP):

An optimal/ feasible solution is any point in the feasible region that gives a maximum or minimum value if substituted in the objective function.

Here feasible region of an LPP is defined as:

A feasible region is that common region determined by all the constraints including the non-negative constraints of the LPP.

So the Feasible region of a LPP is a convex polygon where, its vertices (or corner points) determine the optimal values (either maximum/minimum) of the objective function.

For Example,

5x + y ≤ 100 ; x + y ≤ 60 ; x ≥ 0 ; y ≥ 0

The feasible solution of the LPP is given by the convex polygon OADC.


Here, points O, A ,D and C will be optimal solutions of the taken LPP

Can you explain the answer of this question below:

A ……… of a feasible region is a point in the region, which is the intersection of two boundary lines.​

  • A:

    Section point

  • B:

    Corner point

  • C:

    Reasonable point

  • D:

    Vertex point

The answer is b.

Rahul Bansal answered
Corner Point:
A vertex of the feasible region. Not every intersection of lines is a corner point. The corner points only occur at a vertex of the feasible region. If there is going to be an optimal solution to a linear programming problem, it will occur at one or more corner points, or on a line segment between two corner points.

In linear programming, optimal solution
  • a)
    satisfies all the constraints only
  • b)
    is not unique
  • c)
    satisfies all the constraints as well as the objective function
  • d)
    maximizes the objective function only
Correct answer is option 'C'. Can you explain this answer?

Sameer Saha answered
Linear Programming and Optimal Solution

Introduction to Linear Programming:
Linear programming is a mathematical optimization technique that helps to optimize a linear objective function subject to a set of linear constraints. It is widely used in various fields such as economics, engineering, operations research, and management.

Optimal Solution in Linear Programming:
The optimal solution in linear programming refers to the best possible solution that satisfies both the objective function and the given constraints. It represents the optimal values of the decision variables that maximize or minimize the objective function while satisfying all the constraints.

Satisfying the Constraints:
The optimal solution should satisfy all the constraints given in the linear programming problem. These constraints define the limitations and boundaries within which the decision variables can vary. The optimal solution ensures that all these constraints are met.

Satisfying the Objective Function:
In addition to satisfying the constraints, the optimal solution should also satisfy the objective function. The objective function represents the goal or objective of the linear programming problem. It can be either maximized or minimized based on the problem's requirements. The optimal solution ensures that the objective function is optimized to its maximum or minimum value.

Uniqueness of Optimal Solution:
The uniqueness of the optimal solution depends on the specific linear programming problem. In some cases, the optimal solution may be unique, meaning there is only one solution that satisfies all the constraints and optimizes the objective function. However, in other cases, there may be multiple optimal solutions that yield the same optimal value for the objective function.

Conclusion:
In linear programming, the optimal solution is the solution that satisfies both the constraints and the objective function. It ensures that all the constraints are met and the objective function is optimized. While the optimal solution may or may not be unique, it represents the best possible solution according to the given problem's requirements.

Maximize Z = – x + 2y, subject to the constraints: x ≥ 3, x + y ≥ 5, x + 2y ≥ 6, y ≥ 0.
  • a)
    Maximum Z = 12 at (2, 6)
  • b)
    Z has no maximum value
  • c)
    Maximum Z = 10 at (2, 6)
  • d)
    Maximum Z = 14 at (2, 6)
Correct answer is option 'B'. Can you explain this answer?

Sushant Khanna answered
Objective function is Z = - x + 2 y ……………………(1).
The given constraints are : x ≥ 3, x + y ≥ 5, x + 2y ≥ 6, y ≥ 0.
Corner points Z =  - x + 2y

Here , the open half plane has points in common with the feasible region .
Therefore , Z has no maximum value.

Shape of the feasible region formed by the following constraints is x + y ≤ 2, x + y ≥ 5, x ≥ 0, y ≥ 0​
  • a)
    No feasible region
  • b)
    Triangular region
  • c)
    Unbounded solution
  • d)
    Trapezium
Correct answer is option 'A'. Can you explain this answer?

Prajjawal Sahu answered
No feasible region simply means that no solution Since equation 1 and 2 have no common area

Hence Correct Answer is Option (A)

For chapter Notes on Linear Programming click on the link given below:

The maximum value of Z = 4x + 3y subjected to the constraints 3x + 2y ≤ 160, 5x + 2y ≤ 200, x + 2y ≤ 80 ;
x, y ≥ 0 attains at​
  • a)
    x = 40, y = 0
  • b)
    x = 40, y = 25
  • c)
    x = 0, y = 25
  • d)
    x = 30. y = 25
Correct answer is option 'D'. Can you explain this answer?

Harshad Nair answered
Given object function is

Z = 4x+3y

Constraints are

3x + 2y ≥ 160

5x + 2y ≥ 200

x + 2y ≥ 80

x ≥ 0

y≥ 0.

Consider, the inequalities as equalities for some time,

3x + 2y = 160 ; 5x + 2y = 200 and x + 2y = 80

If we convert these into intercept line format equations, we get,

[Dividing the whole equation with the right hand side number of the equation]


From this form of line, we can say that the line 3x + 2y = 160 meets the x-axis at (,0) and y-axis at (0,80).

This shows the inequality 3x + 2y ≥ 160 holds.


Similarly, from the intercept line format, we can say that the line 5x + 2y = 200 meets the x-axis at (40,0) and y-axis at (0,100).

This shows the inequality 5x + 2y ≥ 200 holds .


Similarly from the intercept line format, we can say that the line x + 2y = 80 meets the x-axis at (80,0) and y-axis at (0,40).

This shows the inequality x + 2y ≥ 80 holds .


Now considering the inequalities, x ≥ 0 and y ≥ 0, this clearly shows the region where both x and y are positive. This represents the 1st quadrant of the graph.

So, the solutions of the LPP are in the first quadrant where the inequalities meet.

Now by plotting all the graphs 3x + 2y ≥ 160 , 5x + 2y ≥ 200 and x + 2y ≥ 80 we get the below graph.


We can clearly see that, there is no area in the 1st quadrant where all the three inequalities met.

This clearly says that there is no solution for the LPP with the given constraints.

Hence the option D, is the solution to the problem.

A maximum or a minimum may not exist for a linear programming problem if
  • a)
    The feasible region is bounded
  • b)
    if the constraints are non linear
  • c)
    if the objective function is continuous
  • d)
    The feasible region is unbounded
Correct answer is option 'D'. Can you explain this answer?

Arnav Datta answered
Introduction:
Linear programming is a mathematical technique used to determine the best possible outcome in a given mathematical model with linear relationships. It involves optimizing an objective function while satisfying a set of constraints. The feasible region represents the set of all possible solutions that satisfy these constraints.

Explanation:
In linear programming, a maximum or a minimum may not exist for a problem under certain conditions. Let's analyze these conditions one by one:

1. Bounded feasible region:
If the feasible region is bounded, it means that there are finite boundaries or limits to the values that the decision variables can take. In such cases, a maximum or a minimum always exists because the feasible region is finite. Therefore, option 'A' is incorrect.

2. Nonlinear constraints:
Linear programming deals with linear constraints, which means that the constraints can be represented by linear equations or inequalities. If the constraints are nonlinear, it implies that the relationships between the decision variables are not linear. In such cases, the problem becomes a nonlinear programming problem, and linear programming techniques may not be applicable. Therefore, option 'B' is incorrect.

3. Continuous objective function:
The objective function represents the quantity that needs to be maximized or minimized. In linear programming, the objective function is always assumed to be continuous. A continuous function is one that does not have any abrupt changes or discontinuities. The continuity of the objective function ensures that a maximum or a minimum can be achieved within the feasible region. Therefore, option 'C' is incorrect.

4. Unbounded feasible region:
If the feasible region is unbounded, it means that there are no finite boundaries or limits to the values that the decision variables can take. In such cases, the solution space extends infinitely in one or more directions, and a maximum or a minimum may not exist. This happens when there are no constraints that restrict the decision variables sufficiently to achieve a finite solution. Therefore, option 'D' is correct.

Conclusion:
In summary, a maximum or a minimum may not exist for a linear programming problem if the feasible region is unbounded. This occurs when there are no constraints that limit the decision variables sufficiently to achieve a finite solution.

A factory makes tennis rackets and cricket bats. A tennis racket takes 1.5 hours of machine time and 3 hours of craftman’s time in its making while a cricket bat takes 3 hour of machine time and 1 hour of craftman’s time. In a day, the factory has the availability of not more than 42 hours of machine time and 24 hours of craftsman’s time. If the profit on a racket and on a bat is Rs 20 and Rs 10 respectively, find the maximum profit of the factory when it works at full capacity?
  • a)
    Maximum profit = Rs 220
  • b)
    Maximum profit = Rs 210
  • c)
    Maximum profit = Rs 200
  • d)
    Maximum profit = Rs 230
Correct answer is option 'C'. Can you explain this answer?

Ujwal Chawla answered
Let number of rackets made = x 
And number of bats made = y 
Therefore , the above L.P.P. is given as : 
Maximise , Z = x +y , subject to the constraints : 1.5x +3y ≤ 42 and. 3x +y ≤ 24, i.e.0.5x + y ≤ 14 i.e. x +2y ≤ 28 and 3x +y ≤ 24 , x, y ≥ 0.

Here Z = 16 is maximum. i.e Maximum number of rackets = 4 and number of bats = 12.
Here , profit function is P = 20x + 10y 
Profit is maximum at x = 4 and y = 12 . 
Therefore , maximum profit = 20(4) + 10 ( 12) = 200.i.e. Rs.200.

The linear inequalities or equations or restrictions on the variables of a linear programming problem are called …… The conditions x ≥ 0 , y ≥ 0 are called …….​
  • a)
    Objective functions, optimal value
  • b)
    Constraints, non-negative restrictions
  • c)
    Objective functions, non-negative restrictions
  • d)
    Constraints, negative restrictions
Correct answer is option 'B'. Can you explain this answer?

Abhay Chauhan answered
Understanding Linear Programming Terms
Linear programming is a mathematical method used to maximize or minimize a linear objective function, subject to a set of linear inequalities or equations. In this context, it’s essential to differentiate between various components of the problem.
What are Constraints?
- Constraints are the linear inequalities or equations that limit the values of the variables in a linear programming problem.
- They define the feasible region, representing all possible solutions that satisfy these restrictions.
- For example, if we have constraints like x + y ≤ 10, this means that the sum of x and y cannot exceed 10.
What are Non-Negative Restrictions?
- The conditions x ≥ 0 and y ≥ 0 are referred to as non-negative restrictions.
- These ensure that the values of the variables are not negative, which is crucial in many real-world scenarios, such as production quantities or resource allocations.
- Non-negativity is integral to ensuring realistic and practical solutions in linear programming problems.
Why Option B is Correct?
- The correct answer is option 'B' because it appropriately labels the linear inequalities as "constraints" and the conditions x ≥ 0, y ≥ 0 as "non-negative restrictions."
- This terminology aligns with standard definitions in linear programming, making it crucial for understanding the problem structure and finding optimal solutions.
In summary, recognizing the terminology in linear programming helps clarify the problem and guides the approach to finding feasible and optimal solutions.

Infeasibility means that the number of solutions to the linear programming models that satisfies all constraints is​
  • a)
    At least 1
  • b)
    An infinite number
  • c)
    Zero
  • d)
    At least 2
Correct answer is option 'C'. Can you explain this answer?

Infeasibility in linear programming models refers to a situation where there are no feasible solutions that satisfy all the constraints. Let's understand this concept in detail.

Feasible Solution:
A feasible solution in linear programming is a solution that satisfies all the given constraints. It is a point that lies within the feasible region, which is defined by the intersection of all the constraints.

Infeasible Solution:
On the other hand, an infeasible solution is a solution that violates one or more constraints. It is a point that lies outside the feasible region and cannot be achieved given the constraints.

Number of Solutions:
Now, let's discuss the number of solutions to a linear programming model that satisfies all the constraints. This can be classified into four possibilities:

1. At least 1 solution: In some cases, there may be only one feasible solution that satisfies all the constraints. This means that there is a unique optimal solution to the linear programming problem.

2. An infinite number of solutions: In certain situations, there might be an infinite number of feasible solutions that satisfy all the constraints. This occurs when the constraints are not restrictive enough to define a unique solution.

3. Zero solutions (Infeasible): Infeasibility occurs when there are no feasible solutions that satisfy all the constraints. This happens when the constraints are contradictory or when they overlap in such a way that no feasible region exists.

4. At least 2 solutions: It is possible to have multiple feasible solutions that satisfy all the constraints. In such cases, the objective function may have multiple optimal solutions, and the decision-maker can choose any of them.

Correct Answer:
In the given question, the correct answer is option 'C', which states that the number of solutions to the linear programming models that satisfy all the constraints is zero. This means that the given constraints are contradictory or overlapping in such a way that no feasible solution exists.

By understanding the concept of infeasibility and the possible number of solutions in linear programming, we can analyze the feasibility of a problem and determine whether it is solvable or not.

Two godowns A and B have grain capacity of 100 quintals and 50 quintals respectively. They supply to 3 ration shops, D, E and F whose requirements are 60, 50 and 40 quintals respectively. The cost of transportation per quintal from the godowns to the shops are given in the following table:

How should the supplies be transported in order that the transportation cost is minimum? What is the minimum cost?
  • a)
    From A : 12,52, 40 units; From B: 50,0,0 units to D, E and F respectively and minimum cost = Rs 530
  • b)
    From A : 10,52, 42 units; From B: 50,0,0 units to D, E and F respectively and minimum cost = Rs 550
  • c)
    From A : 10,50, 40 units; From B: 50,0,0 units to D, E and F respectively and minimum cost = Rs 510
  • d)
    From A : 10,53, 44 units; From B: 50,0,0 units to D, E and F respectively and minimum cost = Rs 570
Correct answer is option 'C'. Can you explain this answer?

Ujwal Chawla answered
Let the number of units of grain transported from godown A to D = x And the number of units of grain transported from godown A to E = y Therefore , the number of units of grain transported from godown A to F = 100 – (x+y) Therefore , the number of units of grain transported from godown B to D = 60 – x The number of units of grain transported from godown B to E = 50 – y The number of units of grain transported from godown B to F = x + y – 60 . Here , the objective function is :Minimise Z = 2.5x + 1.5y + 410 . , subject to constraints : 60 - x ≥ 0,50 - y ≥ 0 ,100 – (x + y) ≥ 0 , (x + y) - 60 ≥ 0 , x,y ≥ 0.

Here Z = 510 is minimum.i.e. From A : 10,50, 40 units; From B: 50,0,0 units to D, E and F respectively and minimum cost = Rs 510 .

Shape of feasible region formed by following constraints is 4x + y ≥ 20, 2x + 3y ≥ 30, x, y ≥ 0.​
  • a)
    Trapezium
  • b)
    Triangular region
  • c)
    Unbounded region and shape is not fixed
  • d)
    No feasible region
Correct answer is option 'C'. Can you explain this answer?

Understanding the Constraints
To analyze the feasible region formed by the constraints:
1. 4x + y ≤ 20
2. 2x + 3y ≤ 30
3. x ≥ 0
4. y ≥ 0
We must first examine each constraint graphically.
Graphical Representation
- The line 4x + y = 20 intersects the axes at points (5, 0) and (0, 20).
- The line 2x + 3y = 30 intersects the axes at points (15, 0) and (0, 10).
Feasible Region Analysis
- The feasible region is the area where all constraints overlap and is bounded by these lines and the axes.
- Both constraints, when graphed, create a region that is not fully enclosed due to the nature of the lines and the positive quadrant restrictions.
Unbounded Region
- As you continue to extend the lines, you will notice that the feasible region expands infinitely in at least one direction.
- The region is unbounded because the lines do not intersect in a way that closes off the area completely.
Conclusion
- Since the feasible region does not form a complete and closed shape, it is classified as an unbounded region.
- Thus, the correct answer is option 'C': Unbounded region and shape is not fixed.
This means that while the constraints limit the values of x and y, they do not create a bounded area, confirming the nature of the feasible region.

Chapter doubts & questions for Linear Programming - Applied Mathematics for Class 12 2025 is part of Commerce exam preparation. The chapters have been prepared according to the Commerce exam syllabus. The Chapter doubts & questions, notes, tests & MCQs are made for Commerce 2025 Exam. Find important definitions, questions, notes, meanings, examples, exercises, MCQs and online tests here.

Chapter doubts & questions of Linear Programming - Applied Mathematics for Class 12 in English & Hindi are available as part of Commerce exam. Download more important topics, notes, lectures and mock test series for Commerce Exam by signing up for free.

Top Courses Commerce