dt1.php

<?php
$arr = array(3,6,7,9,10);
$tot = 0;
foreach($arr as $val){
	$tot += $val;
}
echo $tot/count($arr);

?>

dt2.php

<?php
$arr = "NOISE";
$alpha ="IOSHZXN";
for( $i=0; $i < strlen($arr);$i++){
	$achar = $arr[$i];
	$bad = 1;

	for($x=0; $x<strlen($alpha); $x++){
		if($alpha[$x] == $achar){
			$bad = 0;
		}
	}
	if($bad == 1){
		die("NO");
	}
}
echo "YES!";
?>

Question2.php

<?php
$arr = array(3,6,7,9,10,6,7,2,1);
$count = 0;
foreach ($arr as $value) {
	if($value >= 5){
$count++;
	}
}
echo $count;
?>