Linear Programming: 3 marks Questions (CBSE Class 12)
8 different 3 marks questions on Linear Programming from CBSE Class 12 Maths board exams 2026, newest first.
Solve the following linear programming problem graphically :
Minimize Z=13x−15y
Subject to constraints
x+y≤7,
2x−3y+6≥0,
x≥0,y≥0
Show answer & solution
Answer: Minimum Z = −30 at (0, 2)
- Lines: x+y=7 and 2x−3y+6=0 (through (0, 2) and (-3, 0)).
- They meet where 2(7−y)−3y+6=0⇒y=4,x=3.
- The feasible region is bounded with corner points O(0, 0), A(7, 0), B(3, 4), C(0, 2).
- Z at these: 0, 91, 39 - 60 = -21, -30.
- Minimum Z = −30 at (0, 2).
Solve the following linear programming problem graphically :
Maximize Z=10500x+9000y
Subject to constraints
x+y≤50
2x+y≤80
x,y≥0
Show answer & solution
Answer: Maximum Z=495000 at x=30, y=20
- Lines: x+y=50 through (50,0), (0,50); 2x+y=80 through (40,0), (0,80); they meet at (30,20).
- The feasible region (origin side of both lines, first quadrant) has corners O(0,0), A(40,0), B(30,20), C(0,50).
- Z(O)=0, Z(A)=420000, Z(B)=315000+180000=495000, Z(C)=450000.
- Maximum Z=495000 at (30,20).
Solve the following linear programming problem graphically :
Maximize Z=8000x+12000y
Subject to constraints
3x+4y≤60
x+3y≤30
x≥0, y≥0
Show answer & solution
Answer: Maximum Z=168000 at x=12, y=6
- Lines: 3x+4y=60 through (20,0), (0,15); x+3y=30 through (30,0), (0,10); they meet at (12,6).
- Feasible region corners: O(0,0), A(20,0), B(12,6), C(0,10).
- Z(O)=0, Z(A)=160000, Z(B)=96000+72000=168000, Z(C)=120000.
- Maximum Z=168000 at (12,6).
Solve the following linear programming problem graphically :
Maximize Z=4500x+5000y
Subject to constraints
x+y≤250
25x+40y≤7000
x≥0, y≥0
Show answer & solution
Answer: Maximum Z=1150000 at x=200, y=50
- Lines: x+y=250 through (250,0), (0,250); 25x+40y=7000 through (280,0), (0,175); they meet at (200,50).
- Feasible region corners: O(0,0), A(250,0), B(200,50), C(0,175).
- Z(O)=0, Z(A)=1125000, Z(B)=900000+250000=1150000, Z(C)=875000.
- Maximum Z=1150000 at (200,50).
Solve the following Linear Programming Problem graphically :
Maximise Z=200x+120y
subject to the constraints
x+y≤300
3x+y≤600
x−y≥−100
x,y≥0
Show answer & solution
Answer: Maximum Z = 48000 at x = 150, y = 150
- Draw x+y=300, 3x+y=600 and x−y=−100 in the first quadrant; the feasible region is the bounded region on the origin side of the first two lines and below y=x+100.
- Corner points: O(0, 0), (200, 0), (150, 150) [from x+y=300, 3x+y=600], (100, 200) [from x+y=300, y=x+100], (0, 100).
- Z at these points: 0, 40000, 48000, 44000, 12000.
- Maximum Z=48000 at (150,150).
Solve the following Linear Programming Problem graphically :
Minimize Z=20x+10y
subject to
x+2y≤40
3x+y≥30
4x+3y≥60
x,y≥0
Show answer & solution
Answer: Minimum Z = 240 at x = 6, y = 12
- Draw x+2y=40, 3x+y=30 and 4x+3y=60; the feasible region lies below the first line and above the other two, in the first quadrant (bounded).
- Corner points: (15, 0), (40, 0), (4, 18) [from x+2y=40, 3x+y=30], (6, 12) [from 3x+y=30, 4x+3y=60].
- Z at these points: 300, 800, 260, 240.
- Minimum Z=240 at (6,12).
Solve the following Linear Programming Problem graphically :
Maximize Z=20x+10y
subject to constraints
x+2y≤28
3x+y≤24
x≥2
x,y≥0
Show answer & solution
Answer: Maximum Z = 200 at x = 4, y = 12
- Draw x+2y=28, 3x+y=24 and x=2; the feasible region is the bounded region right of x=2, above the x-axis and below both lines.
- Corner points: (2, 0), (8, 0), (4, 12) [from x+2y=28, 3x+y=24], (2, 13).
- Z at these points: 40, 160, 200, 170.
- Maximum Z=200 at (4,12).
Solve the following Linear Programming Problem graphically :
Maximize Z=52x+103y
subject to constraints
2x+y≤1000
x+y≤800
x,y≥0.
Show answer & solution
Answer: Maximum Z = 260 at x = 200, y = 600.
- Draw 2x+y=1000 through (500, 0), (0, 1000) and x+y=800 through (800, 0), (0, 800); they meet at (200, 600).
- Feasible region (towards the origin, in the first quadrant) has corners (0, 0), (500, 0), (200, 600), (0, 800).
- Z values: 0, 200, 260, 240.
- Maximum Z = 260 at (200, 600).
Practise smarter: chapter-wise revision, formula sheets and step-by-step NCERT solutions on
MonoMath CBSE →