Dear Limesurvey-Experts
I use Version 2.06lts Build 160524

I have a problem with randomization and picking a certain number of question groups. My survey right now has 21 question-groups. Within every question-group, all the questions must be answered. Every participant needs to answer question-group 1(intro), 20 and 21(demographics). Since the survey would be extremely exhausting to answer because it contains more than 200 questions in total, I thought I let the users just answer 6 question groups from question-group 2-19.
How can I make 3 different question-group packages (namely question groups 1,2,3,4,5,6,7, 20,21 and 1,8,9,10,11,12, 13, 20,21 and 1,14,15,16,17,18, 19, 20,21) and evenly distribute the users to the three different packages of question groups?

The survey should have this structure afterwards:

question-group 1 (intro)
6 questions-groups picked from my question groups 2-19
question-group 20 (mandatory)
question-group 21(demographical questions)

Is there an solution to my problem without coding?
(I already tried to insert a new question for randomization for 2 Groups with {rand(1,2)} or {if(randnumber > 0, randnumber, rand(1, 2))} and then in my Question groups into the relevance field randnumber==1or randnumber==2 but it`s unfortunately not working)


If someone could help me I would be extremely thankful!

Create an equation question (hidden via CSS) "randnumber" to generate a random number between 1 and 3.


The relevance for groups 2,3,4,5,6,7 would be randnumber == '1'.
The relevance for groups 8,9,10,11,12,13 would be randnumber == '2'.
The relevance for groups 14,15,16,17,18,19 would be randnumber == '3'.

Hello tpartner, thank you so much for your help!!!
I typed in all your instructions (see example screenshots attached (in german settings))
But now I have the problem, that in preview it only shows me my first and two last question groups (1, 20&21) an none of the ones I wanted to randomize. Where did they go?