I completed the entire samples on ContactList.vsp as directed, and with no Problems but after Saving it many times, the Pagination does not show on preview.  Please let me know if you see any errors.  All the code snippets were copied from the Trailhead Module.  Here's the code:

<apex:page standardController="Contact" recordSetVar="contacts">
    <apex:form >
        <apex:pageBlock title="Contacts List" id="contacts_list">
            
            Filter: 
                <apex:selectList value="{! filterId }" size="1">
                 <apex:selectOptions value="{! listViewOptions }"/>
                <apex:actionSupport event="onchange" reRender="contacts_list"/>
                </apex:selectList>
            
            <!-- Contacts List -->
            <apex:pageBlockTable value="{! contacts }" var="ct">
<!-- Pagination -->
<table style="width: 100%"><tr>

    <td>
Page: <apex:outputText value=" {!PageNumber} of {! CEILING(ResultSize / PageSize) }"/>    </td>            

    <td align="center">
<!-- Previous page -->
<!-- active -->
<apex:commandLink action="{! Previous }" value="« Previous"
     rendered="{! HasPrevious }"/>
<!-- inactive (no earlier pages) -->
<apex:outputText style="color: #ccc;" value="« Previous"
     rendered="{! NOT(HasPrevious) }"/>

&nbsp;&nbsp;  

<!-- Next page -->
<!-- active -->
<apex:commandLink action="{! Next }" value="Next »"
     rendered="{! HasNext }"/>
<!-- inactive (no more pages) -->
<apex:outputText style="color: #ccc;" value="Next »"
     rendered="{! NOT(HasNext) }"/>
    </td>
    
    <td align="right">
Records per page:
<apex:selectList value="{! PageSize }" size="1">
    <apex:selectOption itemValue="5" itemLabel="5"/>
    <apex:selectOption itemValue="20" itemLabel="20"/>
    <apex:actionSupport event="onchange" reRender="contacts_list"/>
</apex:selectList>
    </td>

</tr></table>

                <apex:column value="{! ct.FirstName }"/>
                <apex:column value="{! ct.LastName }"/>
                <apex:column value="{! ct.Email }"/>
                <apex:column value="{! ct.Account.Name }"/>
            </apex:pageBlockTable>
         
        </apex:pageBlock>
     </apex:form>
</apex:page>