Flexslider: randomize slideshow speed of multiple slideshows

Flexslider_randomize_slideshow_speed_of_multiple_slideshows.css

.slider_wrapper {
  float:left;
  width:33%;
}

Flexslider_randomize_slideshow_speed_of_multiple_slideshows.html

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<script src="//cdn.jsdelivr.net/flexslider/2.4/jquery.flexslider-min.js"></script>
<link href="//cdn.jsdelivr.net/flexslider/2.4/flexslider.css" rel="stylesheet" />
<div class="slider_wrapper">
  <div class="flexslider" data-height="250">
    <ul class="slides">
      <li>
        <img src="http://placehold.it/250/000000/ffffff" alt="" />
      </li>
      <li>
        <img src="http://placehold.it/250/ff0000/ffffff" alt="" />
      </li>
      <li>
        <img src="http://placehold.it/250/0000ff/000000" alt="" />
      </li>
    </ul>
  </div>
</div>
<div class="slider_wrapper">
  <div class="flexslider" data-height="250">
    <ul class="slides">
      <li>
        <img src="http://placehold.it/250/000000/ffffff" alt="" />
      </li>
      <li>
        <img src="http://placehold.it/250/ff0000/ffffff" alt="" />
      </li>
      <li>
        <img src="http://placehold.it/250/0000ff/000000" alt="" />
      </li>
    </ul>
  </div>
</div>
<div class="slider_wrapper">
  <div class="flexslider" data-height="250">
    <ul class="slides">
      <li>
        <img src="http://placehold.it/250/000000/ffffff" alt="" />
      </li>
      <li>
        <img src="http://placehold.it/250/ff0000/ffffff" alt="" />
      </li>
      <li>
        <img src="http://placehold.it/250/0000ff/000000" alt="" />
      </li>
    </ul>
  </div>
</div>

Flexslider_randomize_slideshow_speed_of_multiple_slideshows.js

jQuery(document).ready(function($) {
  $('.slider_wrapper').each(function() {
    $(this).flexslider({
      // other options
      randomize: true,
      slideshowSpeed: getRandomInt(1000, 5000)
    });
  });

  function getRandomInt(min, max) {
    return Math.floor(Math.random() * (max - min)) + min;
  }
});