NCERT Solutions for Class 12 Maths Chapter 12 Linear Programming Ex 12.1

In this chapter, we provide NCERT Solutions for Class 12 Maths Chapter 12 Linear Programming Ex 12.1 for English medium students, Which will very helpful for every student in their exams. Students can download the latest NCERT Solutions for Class 12 Maths Chapter 12 Linear Programming Ex 12.1 pdf, free NCERT solutions for Class 12 Maths Chapter 12 Linear Programming Ex 12.1 book pdf download.

BoardCBSE
TextbookNCERT
ClassClass 12
SubjectMaths
ChapterChapter 12
Chapter NameLinear Programming
ExerciseEx 12.1
Number of Questions Solved10
CategoryNCERT Solutions

NCERT Solutions for Class 12 Maths Chapter 12 Linear Programming Ex 12.1

Solve the following Linear Programming Problems graphically:

Ex 12.1 Class 12 Maths Question 1.
Maximize Z = 3x + 4y
subject to the constraints:
x + y ≤ 4,x ≥ 0,y ≥ 0.
Solution:
As x ≥ 0, y ≥ 0, therefore we shall shade the other inequalities in the first quadrant only. Now consider x + y ≤ 4.
Let x + y = 4 => frac { x }{ 4 } +frac { y }{ 4 } =1
Thus the line has 4 and 4 as intercepts along the axes. Now (0, 0) satisfies the inequation i.e., 0 + 0 ≤ 4. Now shaded region OAB is the feasible solution.
NCERT Solutions for Class 12 Maths Chapter 12 Linear Programming 1

Ex 12.1 Class 12 Maths Question 2.
Minimize Z = -3x+4y
subject to x + 2y ≤ 8,3x + 2y ≤ 12, x ≥ 0, y ≥ 0
Solution:
Objective function Z = -3x + 4y
constraints are x+2y ≤ 8,
3x + 2y ≤ 12, x ≥ 0,y ≥ 0
(i) Consider the line x+2y = 8. It pass through A (8,0) and B (0,4), putting x = 0, y = 0 in x + 2y ≤ 8,0 ≤ 8 which is true.
=> region x + 2y ≤ 8 lies on and below AB.
NCERT Solutions for Class 12 Maths Chapter 12 Linear Programming 2
NCERT Solutions for Class 12 Maths Chapter 12 Linear Programming 2.1

Ex 12.1 Class 12 Maths Question 3.
Maximize Z = 5x+3y
subject to 3x + 5y ≤ 15,5x + 2y ≤ 10, x≥0, y≥0
Solution:
The objective function is Z = 5x + 3y constraints
are 3x + 5y≤15, 5x + 2y≤10,x≥0,y≥0
vedantu class 12 maths Chapter 12 Linear Programming 3
NCERT Solutions for Class 12 Maths Chapter 12 Linear Programming 3.1

Ex 12.1 Class 12 Maths Question 4.
Minimize Z = 3x + 5y such that x + 3y ≥ 3, x + y ≥ 2,x,y ≥ 0.
Solution:
For plotting the graph of x + 3y = 3, we have the following table:
NCERT Solutions for Class 12 Maths Chapter 12 Linear Programming 4
NCERT Solutions for Class 12 Maths Chapter 12 Linear Programming 4.1
NCERT Solutions for Class 12 Maths Chapter 12 Linear Programming 4.2

Ex 12.1 Class 12 Maths Question 5.
Maximize Z=3x+2y subject to x+2y ≤ 10, 3x+y ≤ 15, x, y ≥ 0.
Solution:
Consider x + 2y ≤ 10
Let x + 2y = 10
=> frac { x }{ 10 } +frac { y }{ 5 } =1
Now (0,0) satisfies the inequation, therefore the half plane containing (0,0) is the required plane.
Again 3x+2y ≤ 15
Let 3x + y = 15
=> frac { x }{ 5 } +frac { y }{ 15 } =1
It is also satisfies by (0,0) and its required half plane contains (0,0).
Now double shaded region in the first quadrant contains the solution.
NCERT Solutions for Class 12 Maths Chapter 12 Linear Programming 5

Ex 12.1 Class 12 Maths Question 6.
Minimize Z = x + 2y subject to 2x + y ≥ 3, x + 2y ≥ 6, x, y ≥ 0.
Solution:
Consider 2x + y ≥ 3
Let 2x + y = 3
⇒ y = 3 – 2x
vedantu class 12 maths Chapter 12 Linear Programming 6
NCERT Solutions for Class 12 Maths Chapter 12 Linear Programming 6.1
(0,0) is not contained in the required half plane as (0, 0) does not satisfy the inequation 2x + y ≥ 3.
Again consider x+2y≥6
Let x + 2y = 6
=> frac { x }{ 6 } +frac { y }{ 3 } =1
Here also (0,0) does not contain the required half plane. The double-shaded region XABY’ is the solution set. Its comers are A (6,0) and B (0,3). At A, Z = 6 + 0 = 6
At B, Z = 0 + 2 × 3 = 6
We see that at both points the value of Z = 6 which is minimum. In fact at every point on the line AB makes Z=6 which is also minimum.

Show that the minimum of z occurs at more than two points.

Ex 12.1 Class 12 Maths Question 7.
Minimise and Maximise Z = 5x + 10y
subject to x + 2y ≤ 120, x + y ≥ 60, x – 2y ≥ 0, x,y≥0
Solution:
The objective function is Z = 5x + 10y constraints are x + 2y≤120,x+y≥60, x-2y≥0, x,y≥0
NCERT Solutions for Class 12 Maths Chapter 12 Linear Programming 7
vedantu class 12 maths Chapter 12 Linear Programming 7.1

Ex 12.1 Class 12 Maths Question 8.
Minimize and maximize Z = x + 2y subject to x + 2y ≥ 100,2x – y ≤ 0,2x + y ≤ 200;x,y ≥ 0.
Solution:
Consider x + 2y ≥ 100
Let x + 2y = 100
=> frac { x }{ 100 } +frac { y }{ 50 } =1
Now x + 2y ≥ 100 represents which does not include (0,0) as it does not made it true.
Again consider 2x – y ≤ 0
Let 2x – y = 0 or y = 2x
NCERT Solutions for Class 12 Maths Chapter 12 Linear Programming 8
NCERT Solutions for Class 12 Maths Chapter 12 Linear Programming 8.1

Ex 12.1 Class 12 Maths Question 9.
Maximize Z = -x + 2y, subject to the constraints: x≥3, x + y ≥ 5, x + 2y ≥ 6,y ≥ 0
Solution:
The objective function is Z = – x + 2y.
The constraints are x ≥ 3, x + y ≥ 5, x + 2y ≥ 6, y ≥ 0
NCERT Solutions for Class 12 Maths Chapter 12 Linear Programming 9
NCERT Solutions for Class 12 Maths Chapter 12 Linear Programming 9.1

Ex 12.1 Class 12 Maths Question 10.
Maximize Z = x + y subject to x – y≤ -1, -x + y≤0,x,y≥0
Solution:
Objective function Z = x + y, constraints x – y≤ -1, -x + y≤0,x,y≥0
vedantu class 12 maths Chapter 12 Linear Programming 10

All Chapter NCERT Solutions For Class12 Maths

—————————————————————————–

All Subject NCERT Solutions For Class12

*************************************************

Remark:

I think you got complete solutions for this chapter. If You have any queries regarding this chapter, please comment on the below section our subject teacher will answer you. We tried our best to give complete solutions so you got good marks in your exam.

If these solutions have helped you, you can also share Careerkundali.in to your friends.

Best of Luck!!

Leave a Comment

Your email address will not be published. Required fields are marked *