ExpressionScript sample surveys/152/en

From LimeSurvey Manual

The survey has one group containing 10 questions. All questions are assigned the same randomization group name. As a result, they will be displayed in a random order on page load. Each question is given a relevance equation that the sum of the "relevanceStatus" of all other questions in the group is less than the number of questions you want to show. Since relevanceStatus is assigned as questions are rendered, this effectively totals the number of preceding questions.