Q.If number of sources is not equal to number of destinations, the assignment problem is called ________.

$x_{ij}$ is binary: $1$ or $0$.

The assignment problem is a $0$–$1$ (binary) programming model. The decision variable is defined as

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An assignment problem with an equal number of sources and destinations (a square cost matrix) is balanced; if the numbers differ it is unbalanced and must be squared up with dummy rows/columns before applying the Hungarian method.

Reasoning. In an assignment problem the cost matrix has rows = sources and columns = destinations.

• If #sources $=$ #destinations, the matrix is square and the problem is balanced. …