Question 4 Most discrete or integer optimization problems are NPhard to solve, but in certain cases. we may use the linear optimization approach to approximate it. For example, we may[ round the decimal I fractional solutions to the nearest integer values. Discuss the various conditions that we can [or cannot) rely on the rounding-up approach. Give at least one (1') example for each scenario [i.e.5 Scenario 1: roundingup can be used; Scenario 2: roundingup cannot be used). Explain your reasoning and conclusion in detail. {ED marks)