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📐 Mathematics  ·  Linear Programming  ·  JEE

For the furniture problem with constraints 2x + y <= 40, x + 3y <= 60, x >= 0, y >= 0 and objective Z = 30x + 60y, the corner points are (0,0), (20,0), (0,20), and the intersection of the two lines. Find the intersection point.

Answer: (12, 16).

  • A (12, 16)
  • B (15, 10)
  • C (10, 20)
  • D (16, 12)

Correct answer: A. (12, 16)

Explanation: Solve 2x+y=40 and x+3y=60 together. From the first, y=40-2x. Substitute: x+3(40-2x)=60, x+120-6x=60, -5x=-60, x=12, y=40-24=16. Intersection: (12,16).

Feasible Region and Corner PointsxyOABCfeasible regionZ = ax+by is evaluated ONLY at corners O, A, B, C - the optimum is always at one of these

The feasible region (shaded) is bounded by the constraint lines; the fundamental theorem of LPP guarantees the optimal value of the objective function occurs at one of the corner points (O, A, B, C), so only these need to be checked, not the entire region.

Concept context

Optimizing a linear objective function subject to linear constraints using the graphical corner point method.

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