why I get repeated object from List<E> in C#?
<p><strong>this is my question function, I send the collection of data to the ShuffledList function in order to get one row at a time</strong> </p>

<pre><code>  private void nextQuestion_Question()
    {
            ql1 = ShuffleList(ql1);
            currentQuestion_List = ql1.ElementAt(0);
            //ql1.RemoveAt(0);

            txtQ.Text = currentQuestion_List.text;
            btnA.Text = currentQuestion_List.a;
            btnB.Text = currentQuestion_List.b;
            btnC.Text = currentQuestion_List.c;
            btnD.Text = currentQuestion_List.d;

    }
</code></pre>

<p><strong>but this function some times it returns repeated objects</strong>  </p>

<pre><code>private List&lt;E&gt; ShuffleList&lt;E&gt;(List&lt;E&gt; inputList)
    {
        List&lt;E&gt; randomList = new List&lt;E&gt;();
        Random r = new Random();
        int randomIndex = 0;  
               while (inputList.Count&gt;0)
                {
                   randomIndex = r.Next(inputList.Count); //Choose a random object in the list
                    randomList.Add(inputList[randomIndex]); //add it to the new, random list
                    inputList.RemoveAt(randomIndex); //remove to avoid duplicates          
                }
        return randomList; //return the new random list
    }
</code></pre>

<blockquote>
  <p>note I'm try to make a multi choices game and it works well but some times repeat the same questions
  please if you can help me to solve this issue</p>
</blockquote>