List of top Economics Questions on Mathematical Methods in Economics

Given the two matrices \( A = \begin{bmatrix} 1 & 2 \\ 4 & 3 \end{bmatrix} \) and \( B = \begin{bmatrix} 5 & 9 \\ 0 & 3 \end{bmatrix} \), find \( AB \).

Arrange the following steps in the proper sequence concerning the solution of a linear programming problem.

(A) Graph each constraint as though it were binding, i.e., as if held with strict equality
(B) Find the feasible region, the area of the graph that simultaneously satisfies all constraints
(C) Superimpose contours of the objective function on the feasible region to determine the optimal corner of the region
(D) Construct a graph, placing a decision variable on each axis
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Match List-I with List-II

\[\begin{array}{|c|c|}\hline \textbf{List-I} & \textbf{List-II} \\ \hline \text{(A) Closed Interval} & (I)\ [a, b] = \{\,x \in \mathbb{R} : a \leq x \leq b\,\} \\ \hline \text{(B) Open Interval} & (II)\ (a, b) = \{\,x \in \mathbb{R} : a < x < b\,\} \\ \hline \text{(C) Unbounded Interval} & (III)\ [a, b) = \{\,x \in \mathbb{R} : a \leq x < b\,\} \\ \hline \text{(D) Half Open Interval} & (IV)\ (a, \infty) = \{\,x \in \mathbb{R} : a < x\,\} \\ \hline \end{array}\]

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