Here is a solution. It requires a few changes to your HTML, specifically:
- Assign all answers the same class (truth)
- Assign each answer a unique class or ID: (tr1, tr2, etc)
- Assign each question the same class (youcould)
- Assign each question a unique class or ID: (yc1, yc2, etc)
- Make all divs into siblings, not children
Working jsFiddle example
HTML:
<div id="result">
    <div class="truth tr0"><h2>---</h2></div>
    <div class="truth tr1"><h2>answer to one</h2></div>
    <div class="truth tr2"><h2>answer to two</h2></div>
    <div class="truth tr3"><h2>answer to three</h2></div>
    <div class="truth tr4"><h2>answer to four</h2></div>
    <div class="truth tr5"><h2>answer to five</h2></div>
    <div class="truth tr6"><h2>answer to six</h2></div>
 </div>   
<div id="replaceLink">
    <div class="youcould yc1">
        <a href="#2"><h2>QUESTION ONE</h2></a>
    </div>
    <div class="youcould yc2">
        <a href="#3"><h2>QUESTION TWO</h2></a>
    </div>
    <div class="youcould yc3">
        <a href="#4"><h2>QUESTION THREE</h2></a>
    </div>
    <div class="youcould yc4">
        <a href="#5"><h2>QUESTION FOUR</h2></a>
    </div>
    <div class="youcould yc5">
        <a href="#5"><h2>QUESTION FIVE</h2></a>
    </div>
    <div class="youcould yc6">
        <a href="#5"><h2>QUESTION SIX</h2></a>
    </div>
    <div class="youcould yc7">
        <a href="#6"><h2>THANK YOU</h2></a>
    </div>
</div>
<div id="response"></div>
<input type="button" id="mybutt" value="Start Test" />
Javascript/jQuery:
arrDone = [];
$(document).ready(function () {
    //http://stackoverflow.com/questions/1527803/generating-random-numbers-in-javascript-in-a-specific-range
    function getRandomInt (min, max) {
        return Math.floor(Math.random() * (max - min + 1)) + min;
    }
    function nextQues() {
        //If all six questions asked, quit
        if (arrDone.length == 6) return 7;
        success = 0;
        while (success == 0) {
            nn = getRandomInt(1, 6);
            if (arrDone.indexOf(nn) == -1) {
                success++;
                arrDone.push(nn);
            }
        }
        return nn;
    }
    $('.youcould, .truth').hide();
    $('.tr0').show();
    $('.youcould').click(function() {
        $(this).hide();
        //Get last-entered element from array
        thisA = arrDone[arrDone.length -1];
        $('.tr'+thisA).show();
    });
    $('.truth').click(function() {
        $(this).hide();
        if (arrDone.length == 6){
            $(this).removeClass('truth');
            $('#replaceLink').html('<div><h1>Test is Over.</h1><div>');
        }else{
            nextQ = nextQues();
            $('.yc'+nextQ).show();
        }
    });
    $('#mybutt').click(function () {
        $(this).hide();
        $('.tr0').hide();
        nextQ = nextQues();
        $('.yc'+nextQ).show();
    });
}); //END document.ready