JSFiddle - React, Tailwind, and code Playground

HTML

<div id="selected-question"></div>

JavaScript

var cat1 = ["Q1", "Q2", "Q3", "Q4", "Q5"],
    cat2 = ["Q6", "Q7"],
    cat3 = ["Q8", "Q9", "Q10", "Q11", "Q12", "Q13"],
		array = [cat1, cat2, cat3];
    
var whichQuestionArray = array[Math.floor(Math.random() * array.length)],
    selectedQuestion = whichQuestionArray[Math.floor(Math.random() * whichQuestionArray.length)];
document.getElementById("selected-question").innerHTML = selectedQuestion;