Need expert advice on doing it as simply as possible.

My idea would be to first create a T/F question for the actual assessment recording, "Did they get the codes in the correct order?"

This question is actually unseen by the user.

Create a trigger on this slide that will SUBMIT the interaction automatically if the FALSE button is ever selected.  TRUE is the correct answer, however.

On a layer build your question using the desired elements, including your own Submit button which triggers some text evaluations.

1. If code1 = "sun", set T/F = TRUE, else set T/F = False (trigger actually selects the false button)

2. If T/F = True, then: If code2 = "mon" set T/F = TRUE, else set T/F = False

3. If T/F = True, then if code3= "tue" or "wed" or "thu", set T/F = TRUE, else set T/F = False

4. If T/F = True, then if code4= "tue" or "wed" or "thu", set T/F = TRUE, else set T/F = False

5. If T/F = True, then if code5= "tue" or "wed" or "thu", set T/F = TRUE, else set T/F = False

Finally a trigger to SUBMIT the interaction.  If this last trigger ever occurs, it means they got the whole thing correct and the base question is still set to TRUE, so they win.  

If any of the steps 1-5 ever result in FALSE, then the trigger you set on the base question would automatically occur and submit as FALSE and they would fail.

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Not that simple, but I've done things like this in the past to give me some flexibility with what is actually going on in the question, the hidden question just being a T/F test.