include 'per_interface.php'; class student implements per { private $sub1; private $sub2; private $sub3; function __construct($a, $b, $c) { $this->sub1 = $a; $this->sub2 = $b; $this->sub3 = $c; } function total() { $total = $this->sub1 + $this->sub2 + $this->sub3; return $total; } function per() { $per = $this->total() / 3; return $per; } function display() { echo "The percentage score is " . $this->per(); } } $stud1 = new student(12, 12, 12); $stud1->display();