Question 5 of assignment2

Unable to solve question no5 of assignment 2, Kindly provide me the support or source code to solve.
Below is my attempted code to solve the problem also I didnt get what is meant by "height and width should in blue color.

<meta charset="UTF-8">

<meta http-equiv="X-UA-Compatible" content="IE=edge">

<meta name="viewport" content="width=device-width, initial-scale=1.0">

<title>Question5</title>

<style type="text/css">

    table, th, td{

        border: 1px solid blue;

    }

    #centerstyle{

        text-align: center;

    }

    .center{

        text-align: center;

    }

</style>
<h1>Table Structure</h1>

<table style="width: 100%;">

    <tr>

        <th id="centerstyle">Roll number</th>

        <th>first name</th>

        <th>lastname</th>

        <th>address</th>

        <th>height</th>

        <th>width</th>

    </tr>

    <tr>

        <td class="center">1</td>

        <td>Rajat</td>

        <td>Harwadekar</td>

        <td>Karwar</td>

        <td>153cms</td>

        <td>50cms</td>

    </tr>

    <tr>

        <td class="center">2</td>

        <td>Sanat</td>

        <td>Harwadekar</td>

        <td>Bangalore</td>

        <td>158cms</td>

        <td>49cms</td>

    </tr>

    <tr>

        <td class="center">3</td>

        <td>Vaibhav</td>

        <td>Shetti</td>

        <td>Hubli</td>

        <td>145cms</td>

        <td>58cms</td>

    </tr>

    <tr>

        <td class="center">4</td>

        <td>Ganesh</td>

        <td>Manjaguni</td>

        <td>Panvel</td>

        <td>146cms</td>

        <td>53cms</td>

    </tr>

    <tr>

        <td class="center">5</td>

        <td>Pankaj</td>

        <td>Naik</td>

        <td>Pune</td>

        <td>152cms</td>

        <td>49cms</td>

    </tr>

   

</table>