Uncaught ReferenceError: $ is not defined

<script src="https://code.jquery.com/jquery-1.9.1.js"></script>
<script src="path-para-seu-script"></script>

<script src="//ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>

You should put the references to the jquery scripts first.
<script src="jquery-3.5.1.js"></script>
<script type="text/javascript" src="script.js"></script>

<script src="http://ajax.googleapis.com/ajax/libs/jquery/2.0.0/jquery.min.js"></script>
<script type="text/javascript" src="./javascript.js"></script>
<script
    src="http://maps.googleapis.com/maps/api/js?key=YOUR_APIKEY&sensor=false">
</script>

<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js" type="text/javascript"></script>

<script language="JavaScript" type="text/javascript" src="/js/jquery-1.2.6.min.js"></script>
<script language="JavaScript" type="text/javascript" src="/js/jquery-ui-personalized-1.5.2.packed.js"></script>
<script language="JavaScript" type="text/javascript" src="/js/sprinkle.js"></script>

sayHello();