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The maximum value of the objective function Z=8x+2yZ = 8x + 2y of an LPP subject to constraints 2x+y≤3,2x+3y≤6,x≥0,y≥02x + y \leq 3, 2x + 3y \leq 6, x \geq 0, y \geq 0 is:

Solution

✅ Correct Option: 1

The objective function is Z=8x+2yZ = 8x + 2y subject to constraints 2x+y≤32x + y \leq 3, 2x+3y≤62x + 3y \leq 6, x≥0x \geq 0, y≥0y \geq 0.

Since x≥0x \geq 0 and y≥0y \geq 0, the feasible region lies in the first quadrant. The maximum of ZZ occurs at a corner point of the feasible region.


Corner point OO (origin): (0, 0)(0,\ 0)


Corner point AA — line 2x+y=32x + y = 3 meets the xx-axis (y=0y = 0):

2x=32x = 3

x=32x = \tfrac{3}{2}

A=(32, 0)A = \left(\tfrac{3}{2},\ 0\right)


Corner point CC — line 2x+3y=62x + 3y = 6 meets the yy-axis (x=0x = 0):

3y=63y = 6

y=2y = 2

C=(0, 2)C = (0,\ 2)


Corner point BB — intersection of 2x+y=32x + y = 3 and 2x+3y=62x + 3y = 6:

2x+y=3⋯(i)2x + y = 3 \quad \cdots (i)

2x+3y=6⋯(ii)2x + 3y = 6 \quad \cdots (ii)

(ii)−(i)(ii) - (i):

2y=32y = 3

y=32y = \tfrac{3}{2}

From (i)(i):

2x+32=32x + \tfrac{3}{2} = 3

2x=322x = \tfrac{3}{2}

x=34x = \tfrac{3}{4}

B=(34, 32)B = \left(\tfrac{3}{4},\ \tfrac{3}{2}\right)


Evaluating Z=8x+2yZ = 8x + 2y at each corner point:

At O(0, 0)O(0,\ 0): Z=8(0)+2(0)=0Z = 8(0) + 2(0) = 0

At A(32, 0)A\left(\tfrac{3}{2},\ 0\right): Z=8(32)+2(0)=12Z = 8\left(\tfrac{3}{2}\right) + 2(0) = 12

At B(34, 32)B\left(\tfrac{3}{4},\ \tfrac{3}{2}\right): Z=8(34)+2(32)=6+3=9Z = 8\left(\tfrac{3}{4}\right) + 2\left(\tfrac{3}{2}\right) = 6 + 3 = 9

At C(0, 2)C(0,\ 2): Z=8(0)+2(2)=4Z = 8(0) + 2(2) = 4


The maximum value of ZZ is 12\boxed{12} at the point (32, 0)\left(\tfrac{3}{2},\ 0\right).

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