Concept:In a linear programming problem, the maximum value of the objective function occurs at a corner point of the feasible region.
Explanation:The feasible region is bounded by the constraint lines
3x+y=15 and
3x+4y=24, along with the axes
x=0 and
y=0.
First, determine all the corner points of the feasible region.
The origin is
(0,0).
On the x-axis, put
y=0.
Then
3x≤15, so
x≤5.
This gives the corner point
(5,0).
On the y-axis, put
x=0.
Then
4y≤24, so
y≤6.
This gives the corner point
(0,6).
Next, find the intersection of the two boundary lines.
Subtract
3x+y=15 from
3x+4y=24.
This gives
3y=9, so
y=3.
Substitute
y=3 into
3x+y=15.
Then
3x+3=15, so
3x=12 and
x=4.
Thus, the intersection point is
(4,3).
Now evaluate
Z=4x+5y at every corner point.
At
(0,0):
Z=4(0)+5(0)=0At
(5,0):
Z=4(5)+5(0)=20At
(4,3):
Z=4(4)+5(3)=16+15=31At
(0,6):
Z=4(0)+5(6)=30The largest value among these is
31.
Answer:The maximum value of
Z is
31, which matches option A.