Answers
For this question, we need to populate Y column according to the required conditions
Formula for Y = IF(AND(OR(Order="High",Order="Critical"),Mode="Express Air"),"TRUE","FALSE")
The conditions that we require are that the order needs to be either "High" priority or "Critical" priority, so we've used OR(Order="High",Order="Critical") part. Further if the order is either of these and the Mode chosen is Express Air, we want our Y column to show true.
AND(OR(Order="High",Order="Critical"),Mode="Express Air") part checks precisely that.
The if in the beginning checks if the order satisfies all the conditions, and marks TRUE id it does, or FALSE.
The question was not complete in every sense, so this is what I can help you with, this formula can be used to populate the Y column.
Let me know if any issues.