Using LINQ, how do I find an object with a given property value from a List?

I have a class called Questions. This Questions has properties QuestionID and QuestionAnswer. While iterating through this List of Question in foreach, I have to find .QuestionID = 12. If I find .QuestionID = 12 then I have to immediately assign a value to .QuestionAnswer = "SomeText" of .QuestionID = 14.

I don't want iterate again inside .QuestionId = 12' to find.QuestionID = 14` again.

Is there any way I can go directly to .QuestionID = 14 using LINQ?.

For example:

For Each mQuestion As Question In _mQuestions
    If mQuestion.QuestionId = 12 Then
         'Find mQuestion.QuestionID= 14 and insert Somtext to 
          'mQuestion.QuestionAnswer="SomeText"
    End IF
Next