diff -r c70118cdde66 -r a0bec380b44f day1/exercise/duplicate_marks.py
--- a/day1/exercise/duplicate_marks.py	Fri Apr 23 08:49:25 2010 +0530
+++ b/day1/exercise/duplicate_marks.py	Tue Apr 27 12:14:30 2010 +0530
@@ -1,13 +1,18 @@
 students = {
-    'Madhu': 12,
+    'Madhu': 45,
     'Shantanu':45,
     'Puneeth': 54,
     'Vattam': 35,
-    'KD': 50,
+    'KD': 54,
+    'Asokan': 45
     }
 
 all_marks = students.values()
 unique_marks = set(all_marks)
 
 print "Number of Duplicate marks: ", len(all_marks) - len(unique_marks)
-print "Duplicate marks: ", set(all_marks - list(unique_marks))
+
+for i in unique_marks:
+    all_marks.remove(i)
+
+print "Duplicate marks:", set(all_marks)