1. Re-write the ternary operator to if/else:
   echo ( $widgets >= 10 ) ? $plenty : $few;

Ans:
if( $widgets >= 10) 
  echo "$plenty.";
else
  echo "$few.";


2. Re-write the if/else to a ternary operator:
   if($score >= 70)
      echo "You pass the course.<br />";
   else
      echo "You have to retake the course.<br />";

Ans:
$passed = "You pass the course.<br />";
$failed = "You have to retake the course.<br />";
echo ( $score >= 70 ) ? $passed : $failed;


3. Re-write the ternary operator to if/else:
   echo "$x is an ". ($x%2 == 0 ? "even" : "odd") ." number.<br />";

Ans:
if( $x%2 == 0)
   echo "$x is an even number.<br />";
else
   echo "$x is an odd number.<br />";