Advertisements
Advertisements
Question
Solve the following linear programming problems by graphical method.
Maximize Z = 20x1 + 30x2 subject to constraints 3x1 + 3x2 ≤ 36; 5x1 + 2x2 ≤ 50; 2x1 + 6x2 ≤ 60 and x1, x2 ≥ 0.
Advertisements
Solution
Given that 3x1 + 3x2 ≤ 36
Let 3x1 + 3x2 = 36
| x1 | 0 | 12 |
| x2 | 12 | 0 |
Also given that 5x1 + 2x2 ≤ 50
Let 5x1 + 2x2 = 50
| x1 | 0 | 10 |
| x2 | 25 | 0 |
3x1 + 3x2 = 36
x1 + x2 = 12 ……….(1)
5x1 + 2x2 = 50 ………(2)
2x1 + 2x2 = 24 ....[(1) × 2]
− − −
−3x1 = − 6
x1 = 2
Substituting x1 = 2 in (1) we get
2+ x2 = 12
x2 = 6
Also given that 2x1 + 6x2 ≤ 60
Let 2x1 + 6x2 = 60
x1 + 3x2 = 30
| x1 | 0 | 30 |
| x2 | 10 | 0 |
x1 + x2 = 12 …….(1)
x1 + 3x2 = 30 …….(2)
– 2x2 = – 18 ......[Equation (1) – (2)]
x2 = 9
x2 = 9 substitute in (1)
x1 + x2 = 12
x1 + 9 = 12
x1 = 12 – 9
x1 = 3

The feasible region satisfying all the given conditions is OABCD.
The co-ordinates of the comer points are
| Corner points | Z = 20x1 + 30x2 |
| O(0, 0) | 0 |
| A(10, 0) | 200 |
| B(2, 6) | 220 |
| C(3, 9) | 330 |
| D(0, 10) | 300 |
The maximum value of Z occurs at C(3, 9)
∴ The optimal solution is x1 = 3, x2 = 9 and Zmax = 330
APPEARS IN
RELATED QUESTIONS
If John drives a car at a speed of 60 km/hour, he has to spend ₹ 5 per km on petrol. If he drives at a faster speed of 90 km/hour, the cost of petrol increases ₹ 8 per km. He has ₹ 600 to spend on petrol and wishes to travel the maximum distance within an hour. Formulate the above problem as L.P.P.
Solve the following LPP by graphical method:
Maximize z = 11x + 8y, subject to x ≤ 4, y ≤ 6, x + y ≤ 6, x ≥ 0, y ≥ 0
A chemical company produces a chemical containing three basic elements A, B, C, so that it has at least 16 litres of A, 24 litres of B and 18 litres of C. This chemical is made by mixing two compounds I and II. Each unit of compound I has 4 litres of A, 12 litres of B and 2 litres of C. Each unit of compound II has 2 litres of A, 2 litres of B and 6 litres of C. The cost per unit of compound I is ₹ 800 and that of compound II is ₹ 640. Formulate the problems as LPP and solve it to minimize the cost.
A manufacturer produces bulbs and tubes. Each of these must be processed through two machines M1 and M2. A package of bulbs requires 1 hour of work on Machine M1 and 3 hours of work on M2. A package of tubes requires 2 hours on Machine M1 and 4 hours on Machine M2. He earns a profit of ₹ 13.5 per package of bulbs and ₹ 55 per package of tubes. If maximum availability of Machine M1 is 10 hours and that of Machine M2 is 12 hours, then formulate the L.P.P. to maximize the profit.
A train carries at least twice as many first class passengers (y) as second class passengers (x). The constraint is given by ______.
Which value of x is in the solution set of inequality − 2X + Y ≥ 17
Maximize z = 10x + 25y subject to x + y ≤ 5, 0 ≤ x ≤ 3, 0 ≤ y ≤ 3
The constraint that in a particular XII class, number of boys (y) are less than number of girls (x) is given by ______
Solve the following linear programming problems by graphical method.
Maximize Z = 6x1 + 8x2 subject to constraints 30x1 + 20x2 ≤ 300; 5x1 + 10x2 ≤ 110; and x1, x2 ≥ 0.
Solution which satisfy all constraints is called ______ solution.
