All Exams  >   JEE  >   Mathematics (Maths) Class 12  >   All Questions

All questions of Chapter 12 - Linear Programming for JEE 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?

Linear programming is an optimization technique for a system of linear constraints and a linear objective function. An objective function defines the quantity to be optimized, and the goal of linear programming is to find the values of the variables that maximize or minimize the objective function.

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.

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 optimal value of the objective function Z = ax + by may or may not exist, if the feasible region for a LPP is
  • a)
    a circle
  • b)
    a polygon
  • c)
    Bounded
  • d)
    Unbounded
Correct answer is option 'D'. Can you explain this answer?

Akshay Kapoor answered
The optimal value of the objective function Z = ax + by may or may not exist, if the feasible region for a LPP is unbounded.

Explanation:
To understand why the optimal value of the objective function may or may not exist when the feasible region for a Linear Programming Problem (LPP) is unbounded, let's first define what an unbounded feasible region is.

An unbounded feasible region is a region in the graph of the constraints where there are no restrictions on the values of the decision variables. This means that the feasible region extends infinitely in one or more directions.

Optimal Value of the Objective Function:
The optimal value of the objective function refers to the maximum or minimum value that can be achieved for the given objective function within the feasible region. In other words, it represents the best possible value that can be obtained for the objective function.

Possible Scenarios:
When the feasible region is unbounded, there are two possible scenarios in terms of the optimal value of the objective function:

1. Optimal value exists: In some cases, even though the feasible region is unbounded, there may still exist an optimal value for the objective function. This occurs when the objective function is bounded and has a maximum or minimum value within the feasible region. The optimal value can be found at the extreme point(s) of the feasible region.

2. Optimal value does not exist: In other cases, the objective function may not have an optimal value within the unbounded feasible region. This occurs when the objective function is unbounded as well, meaning it can increase or decrease indefinitely without reaching a maximum or minimum value. In such cases, the objective function does not have a finite optimal value.

Conclusion:
Therefore, the optimal value of the objective function Z = ax + by may or may not exist when the feasible region for a LPP is unbounded. It depends on whether the objective function is bounded or unbounded within the feasible region. If the objective function is bounded, an optimal value exists, whereas if the objective function is unbounded, an optimal value does not exist.

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:

A manufacturer produces nuts and bolts. It takes 1 hour of work on machine A and 3 hours on machine B to produce a package of nuts. It takes 3 hours on machine A and 1 hour on machine B to produce a package of bolts. He earns a profit of Rs17.50 per package on nuts and Rs 7.00 per package on bolts. How many packages of each should be produced each day so as to maximise his profit, if he operates his machines for at the most 12 hours a day?
  • a)
    3 packages of nuts and 3 packages of bolts; Maximum profit = Rs 73.50.
  • b)
    4 packages of nuts and 4 packages of bolts; Maximum profit = Rs 76.50.
  • c)
    3 packages of nuts and 4 packages of bolts; Maximum profit = Rs 74.50.
  • d)
    4 packages of nuts and 3 packages of bolts; Maximum profit = Rs 75.50.
Correct answer is option 'A'. Can you explain this answer?

Disha Nair answered
To maximize the profit, we need to determine the number of packages of nuts and bolts that should be produced each day, given the constraints of the machines' operating hours.

Let's assume that x packages of nuts and y packages of bolts are produced each day.

The time constraint can be represented by the following equation:
1x + 3y ≤ 12 (since machine A takes 1 hour for nuts and 3 hours for bolts, and the total operating hours is 12)

Next, we need to consider the profit constraint. The profit for nuts is Rs17.50 per package, and the profit for bolts is Rs7.00 per package.

The profit equation can be represented as:
Profit = 17.50x + 7.00y

To determine the maximum profit, we need to find the maximum value of the profit equation subject to the constraints mentioned above.

Solving the above equations graphically or using linear programming techniques, we find that the maximum profit is obtained when x = 3 and y = 3.

Substituting these values into the profit equation:
Profit = 17.50(3) + 7.00(3) = Rs 52.50 + Rs 21.00 = Rs 73.50

Therefore, the correct answer is option 'A': 3 packages of nuts and 3 packages of bolts, with a maximum profit of Rs 73.50.

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.

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.

Which of the following sets are convex ?​
  • a)
    {(x, y) : x2 + y2 ≥ 1}
  • b)
    {(x,y) : y≥2 , y≤4}
  • c)
    {(x, y) : 3x2 + 4y2 ≥ 5}
  • d)
    {(x, y) : y2 ≥ x}
Correct answer is option 'B'. Can you explain this answer?

Gowri Iyer answered
 {(x,y) : y≥2 , y≤4} is the region between two parallel lines, so any line segment joining any two points in it lies in it. Hence, it is the convex set.

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.

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

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

Mathematics (Maths) Class 12

204 videos|290 docs|139 tests

Signup to see your scores go up within 7 days!

Study with 1000+ FREE Docs, Videos & Tests
10M+ students study on EduRev