When the total demand is equal to supply, then the transportation problem is said to be ______________a.balancedb.unbalancedc.maximisationd.minimisation

The correct answer is a. balanced.

In the context of transportation problems, the terms "balanced" and "unbalanced" refer to the relationship between total supply and total demand. A transportation problem is considered balanced when the total supply from all sources equals the total demand required at all destinations. This means that the amount of goods available for transport perfectly matches the amount required, allowing for an optimal solution without surplus or deficit.

When the problem is balanced, it simplifies the solution process as there will be no excess capacity or unmet needs. On the other hand, an unbalanced transportation problem occurs when either the total supply exceeds total demand or vice versa. In such cases, additional steps are needed to address the imbalance, such as adding a dummy source or destination in order to achieve balance.

To summarize, in a balanced transportation problem, the equation $\text{Total Supply} = \text{Total Demand}$ holds true, leading to a more straightforward approach in finding the optimal allocation of resources.