I have tried to process my web page in the W3C validator. But it always shows that the Start tag head seen but an element of the same type was already open.But If I remove the start tag of `<head>`,it passed. If I add the start tag, the error arises again. Why does this happen.
Here is the my code

```
    <!DOCTYPE html>
<html>
<style type="text/css">
table,th,td{
    border:1px solid black;
}
</style>
<head>
<title>Rui's Calendar</title>
<meta charset="UTF-8">
</head>
 <body>
  <h1>Rui's Calendar</h1>
  <table style="width 100%">
   <tr style="color: blue">
     <th>
      <p>Monday</p> 
     </th>
     <td>
      <p><i>9:00-9:50 AM</i><br>PHY 1302 Willey Hall</p>    
     </td>
     <td>
      <p><i>11:00-12:00 AM</i><br>  -   </p>
     </td>
     <td>
     <p><i>5:45-6:30 PM</i><br>CSCI 4041 Akerman Hall</p>
     </td>
   </tr>
   <tr style="color:red">
     <th>
      <p>Tuesday</p>    
     </th>
     <td>
      <p><i>9:00-9:50 AM</i><br>PHY 1302 <a href="http://campusmaps.umn.edu/willey-hall"></a>>Willey Hall</p>
     </td>
     <td>
      <p><i>1:00-2:15 PM</i><br>CSCI 4707 Fraser Hall</p>
     </td>
     <td>
     <p><i>2:30-3:45 PM</i><br>CSCI 4131 Bruininks Hall</p>
     </td>
   </tr>
   <tr style="color: blue">
     <th>
      <p>Wednesday</p>
     </th>
     <td>
      <p><i>9:00-9:50 AM</i><br>PHY 1302 Blegen Hall</p>    
     </td>
     <td>
      <p><i>1:00-2:15 PM</i><br>-</p>
     </td>
     <td>
     <p><i>2:30-3:45 PM</i><br>-</p>
     </td>
   </tr>
   <tr style="color: red">
     <th>
      <p>Thursday</p>   
     </th>
     <td>
      <p><i>9:00-9:50 AM</i><br>PHY 1302 Blegen Hall</p>    
     </td>
     <td>
      <p><i>1:00-2:15 PM</i><br>CSCI 4707 <a href="http://campusmaps.umn.edu/fraser-hall">Fraser Hall</a></p>
     </td>
     <td>
     <p><i>2:30-3:45 PM</i><br>CSCI 4131 Bruininks Hall</p>
     </td>
   </tr>
   <tr style="color: blue">
     <th>
      <p>Friday</p>>    
     </th>
     <td>
      <p><i>9:00-9:50 AM</i><br>PHY 1302 Willey Hall</p>    
     </td>
     <td>
      <p><i>1:00-2:15 PM</i><br>-</p>
     </td>
     <td>
     <p><i>2:30-3:45 PM</i><br>-</p>
     </td>
   </tr>

  </table>
 </body>
</html>

```