Survey progress bar with a limited randomized number of blocks counted

Got it. Then you will have to add a custom progress bar using javascript. To add a custom progress bar, refer to this discussion. Please copy the custom progress bar code and add it to your look and feel-->header. Also, add the 'pb' embedded data to the start of your survey flow and set it to '0'.
Now you will have to count the total number of questions/block that can be displayed to a user add below JS to each question/bock:
***************JS Starts here*****************
Qualtrics.SurveyEngine.addOnReady(function()
{
var new_pb;
new_pb = Qualtrics.SurveyEngine.getEmbeddedData( 'pb');
var total = parseInt(new_pb) + 10;
Qualtrics.SurveyEngine.setEmbeddedData( 'pb', total);
});
***************JS Ends here*****************
What you are doing is basically incrementing the progress bar by an x percentage either for each question or each block. The sum of these increments should be equal to 100. In the above example, I have incremented it by 10 for each question displayed. My survey has 50 questions but only 10 will be displayed to a respondent.

Hope this makes sense. Let me know if you have any questions.