Question:medium

For the given linear programming problem,
Minimum Z = 6x + 10y
subject to the constraints
\( x \ge 6 \); \( y \ge 2 \); \( 2x+y \ge 10 \); \( x,y \ge 0 \),
the redundant constraints are:

Show Hint

To spot redundant constraints, look for implications. If one constraint (e.g., \(x \ge 6\)) is stricter than another (e.g., \(x \ge 0\)), the less strict one is redundant. Also, check combinations of constraints. If two constraints \(A\) and \(B\) together imply a third constraint \(C\), then \(C\) is redundant.
Updated On: Feb 10, 2026
  • \( x \ge 6, 2x+y \ge 10 \)
  • \( 2x+y \ge 10 \)
  • \( x \ge 6, y \ge 2, x \ge 0, y \ge 0 \)
  • \( y \ge 2, x \ge 0 \)
Show Solution

The Correct Option is B

Solution and Explanation

Step 1: Definition:
A redundant constraint in linear programming doesn't affect the feasible region; removing it doesn't change the set of feasible solutions. Redundant constraints are automatically satisfied when other constraints are met.

Step 2: Analysis:
Examine the following constraints: 1. \( x \ge 6 \) 2. \( y \ge 2 \) 3. \( 2x+y \ge 10 \) 4. \( x \ge 0 \) 5. \( y \ge 0 \) Identify redundant constraints: - \( x \ge 0 \) is redundant because \( x \ge 6 \) implies \(x \ge 0\). - \( y \ge 0 \) is redundant because \( y \ge 2 \) implies \(y \ge 0\). - Consider \( 2x+y \ge 10 \). If \( x \ge 6 \) and \( y \ge 2 \), then the smallest value of \( 2x+y \) is \( 2(6) + 2 = 14 \). Since \( 14>10 \), \( 2x+y \ge 10 \) is satisfied. Thus, \( 2x+y \ge 10 \) is redundant. The non-redundant constraints are \(x \ge 6\) and \(y \ge 2\). The constraints \(x \ge 0\), \(y \ge 0\), and \(2x+y \ge 10\) are redundant. The question asks for the redundant constraints. Evaluate the options: (A) \( x \ge 6, 2x+y \ge 10 \): \(x \ge 6\) is not redundant. (B) \( 2x+y \ge 10 \): This constraint is redundant. (C) \( x \ge 6, y \ge 2, x \ge 0, y \ge 0 \): \(x \ge 6\) and \(y \ge 2\) are not redundant. (D) \( y \ge 2, x \ge 0 \): \(y \ge 2\) is not redundant. The full set of redundant constraints is \( \{2x+y \ge 10, x \ge 0, y \ge 0\} \). Option (B) lists one of these. It is the best choice.

Step 3: Conclusion:
\( x \ge 0 \) and \( y \ge 0 \) are redundant due to \( x \ge 6 \) and \( y \ge 2 \). \( 2x+y \ge 10 \) is also redundant. Therefore, \( 2x+y \ge 10 \) is a redundant constraint.
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