Solve each of the following linear programming problems by graphical method.
Maximize Z = 5x + 3y
Subject to :
3x + 5y ≤ 15
5x + 2y ≤ 10
x, y ≥ 0
Matching exercise
Match the items on the right to the items on the left.
Step - 1
Step - 2
Step - 3
Step - 4
Step - 5
Step - 6
Given,
Objective function is: Z = 5x + 3y
Constraints are:
3x + 5y ≤ 15
5x + 2y ≤ 10
x, y ≥ 0
First convert the given inequations into corresponding equations and plot them:
3x + 5y≤ 15 → 3x + 5y = 15 (corresponding equation)
Two coordinates required to plot the equation are obtained as:
Put, x = 0 ⇒ y = 3 (0,3) - - - - first coordinate.
Put, y = 0 ⇒ x = 5 (5,0) - - - - second coordinate
Join them to get the line.
As we know, Linear inequation will be a region in the plane, and we observe that the equation divides the XY plane into 2 halves only, so we need to check which region represents the given inequation,
If the given line does not pass through origin the just put (0,0) to check whether inequation is satisfied or not. If it satisfies the inequation origin side is the required region else the other side the solution.
Similarly, we repeat the steps for other inequation also and find the common region.
5x + 2y≤ 10 → 5x + 2y = 10 (corresponding equation)
Two coordinates required to plot the equation are obtained as:
Put, x = 0 ⇒ y = 5 (0,5) - - - - first coordinate.
Put, y = 0 ⇒ x = 2 (2,0) - - - - second coordinate
x = 0 is the y - axis and y = 0 is the x - axis
Hence we obtain a plot as shown in figure:
The shaded region in the above figure represents the region of a feasible solution.
Now to maximize our objective function, we need to find the coordinates of the corner points of the shaded region.
We can determine the coordinates graphically our by solving equations.
But choose only those equations to solve which gives one of the corner coordinates of the feasible region.