You could use the relevance equation to display x out of y questions in each group
E.g. if the question names are Q1 to Q10 for Q1 the relevance equation would be:
Code:
sum(Q2.relevanceStatus, Q3.relevanceStatus, Q4.relevanceStatus, Q5.relevanceStatus, Q6.relevanceStatus, Q7.relevanceStatus, Q8.relevanceStatus, Q9.relevanceStatus, Q10.relevanceStatus) LT 5
LT 5 would mean 5 out of 10 will be displayed.
The order has to be randomized (so every question in one group has to get the same randomization group name).
Just modify the example to your needs.