<span style="color:#000000;">two hours and a half's walk</span><br/><br/><span style="color:#000000;">two and a half hours' walk</span><br/><br/><span style="color:#000000;"> </span><br/><br/><span style="color:#000000;">which one is correct?</span><br/><br/><span style="color:#000000;"> </span><br/><br/><span style="color:#000000;">Thank you </span>