OR-I


Q. Solve the following LPP by using graphical method

Maximize Z = x1+x2
Subject to constraints :
x1+x2
x1+x2
and x1,x2≥0.

Answer :

Graphical Method :
Convert the inequality constraints as equalities
x1+x2= - (1)
x1+x2= - (2)
Put x1= 0 in (1) => x2=
Let A = (0, )
Again put x2=0 in (1)=>x1=
Let B = ( ,0)
Put x2= 0 in (2) => x1=
Let C = ( ,0)
Put x1= 0 in (2) => x2=
Let D = (0, )
Using the above four points, construct graph
This is the graph it's real use autoscale option to see graph


Let 'E' be the point of intersection of (1) and (2).
So, solve (1) and (2)
the values of units x1,x2 is
Therefore E = (, )
In the above graph, the feasible region is given by OAEC.
The values of Z at these vertices are given by
Vertex Value of Z=x1+x2
O(0,0) Z=0
A(0,) Z=(0)+()=
E(,) Z=()+()=
C(,0) Z=()+(0)=
Therefore, The problem is of maximization type,the optimum solution of the given problem is:
Maximize Z = ,x1=and x2=