The document contains the answer key for the Post Graduate Common Entrance Test (PG-CET) 2011 for the MTech in Environmental Engineering exam administered by the Karnataka Examinations Authority on September 3, 2011. The answer key lists the correct answers for 75 multiple choice questions as numbers 1 through 4, with some questions having multiple correct answers indicated by values greater than 4. It notes that some answers are marked with a G, indicating one grace mark was awarded for that question.