Index: lams_common/src/java/org/lamsfoundation/lams/qb/model/QbToolAnswer.java
===================================================================
diff -u -r2b3d3b2f61d37cf2fa7cccc0cf4565e5dfc4b88e -r7f09ca6e27d33ac2afa5859c4b482178657748c4
--- lams_common/src/java/org/lamsfoundation/lams/qb/model/QbToolAnswer.java	(.../QbToolAnswer.java)	(revision 2b3d3b2f61d37cf2fa7cccc0cf4565e5dfc4b88e)
+++ lams_common/src/java/org/lamsfoundation/lams/qb/model/QbToolAnswer.java	(.../QbToolAnswer.java)	(revision 7f09ca6e27d33ac2afa5859c4b482178657748c4)
@@ -1,5 +1,7 @@
 package org.lamsfoundation.lams.qb.model;
 
+import java.util.Comparator;
+
 import javax.persistence.Column;
 import javax.persistence.Entity;
 import javax.persistence.FetchType;
@@ -22,7 +24,18 @@
 @Entity
 @Table(name = "lams_qb_tool_answer")
 @Inheritance(strategy = InheritanceType.JOINED)
-public abstract class QbToolAnswer {
+public abstract class QbToolAnswer implements Comparable<QbToolAnswer> {
+    public static final Comparator<QbToolAnswer> COMPARATOR = Comparator
+	    .comparing(a -> a.getQbToolQuestion().getDisplayOrder());
+
+    // it makes sense to put comparator here as an internal class, so we do not need to look for it in other classes
+    public static class QbToolAnswerComparator implements Comparator<QbToolAnswer> {
+	@Override
+	public int compare(QbToolAnswer o1, QbToolAnswer o2) {
+	    return COMPARATOR.compare(o1, o2);
+	}
+    }
+
     @Id
     @Column(name = "answer_uid")
     @GeneratedValue(strategy = GenerationType.IDENTITY)
@@ -39,6 +52,11 @@
     @JoinColumn(name = "qb_option_uid")
     protected QbOption qbOption;
 
+    @Override
+    public int compareTo(QbToolAnswer other) {
+	return COMPARATOR.compare(this, other);
+    }
+
     public Long getUid() {
 	return this.uid;
     }
@@ -84,4 +102,5 @@
 	QbToolAnswer other = (QbToolAnswer) obj;
 	return new EqualsBuilder().append(this.getUid(), other.getUid()).isEquals();
     }
-}
+
+}
\ No newline at end of file
Index: lams_tool_assessment/src/java/org/lamsfoundation/lams/tool/assessment/model/AssessmentQuestionResult.java
===================================================================
diff -u -r0dc158981713b0ab875102e364bd7c4a3a0e2235 -r7f09ca6e27d33ac2afa5859c4b482178657748c4
--- lams_tool_assessment/src/java/org/lamsfoundation/lams/tool/assessment/model/AssessmentQuestionResult.java	(.../AssessmentQuestionResult.java)	(revision 0dc158981713b0ab875102e364bd7c4a3a0e2235)
+++ lams_tool_assessment/src/java/org/lamsfoundation/lams/tool/assessment/model/AssessmentQuestionResult.java	(.../AssessmentQuestionResult.java)	(revision 7f09ca6e27d33ac2afa5859c4b482178657748c4)
@@ -52,7 +52,7 @@
 @Table(name = "tl_laasse10_question_result")
 //in this entity's table primary key is "uid", but it references "answer_uid" in lams_qb_tool_answer
 @PrimaryKeyJoinColumn(name = "uid")
-public class AssessmentQuestionResult extends QbToolAnswer implements Comparable<AssessmentQuestionResult> {
+public class AssessmentQuestionResult extends QbToolAnswer {
 
     @Column(name = "answer_float")
     private float answerFloat;
@@ -224,14 +224,4 @@
     public void setQuestionDto(QuestionDTO questionDto) {
 	this.questionDto = questionDto;
     }
-
-    @Override
-    public int compareTo(AssessmentQuestionResult o) {
-	if (o != null) {
-	    return qbToolQuestion.getDisplayOrder() - o.qbToolQuestion.getDisplayOrder();
-	} else {
-	    return 1;
-	}
-    }
-
-}
+}
\ No newline at end of file
Index: lams_tool_assessment/src/java/org/lamsfoundation/lams/tool/assessment/model/AssessmentResult.java
===================================================================
diff -u -rf280ea4699aa04587b63c0fef3e2a02b7d847c0d -r7f09ca6e27d33ac2afa5859c4b482178657748c4
--- lams_tool_assessment/src/java/org/lamsfoundation/lams/tool/assessment/model/AssessmentResult.java	(.../AssessmentResult.java)	(revision f280ea4699aa04587b63c0fef3e2a02b7d847c0d)
+++ lams_tool_assessment/src/java/org/lamsfoundation/lams/tool/assessment/model/AssessmentResult.java	(.../AssessmentResult.java)	(revision 7f09ca6e27d33ac2afa5859c4b482178657748c4)
@@ -40,6 +40,9 @@
 import javax.persistence.Table;
 import javax.persistence.Transient;
 
+import org.hibernate.annotations.SortComparator;
+import org.lamsfoundation.lams.qb.model.QbToolAnswer;
+
 /**
  * Assessment Result
  *
@@ -87,6 +90,7 @@
 
     @OneToMany(cascade = CascadeType.ALL, fetch = FetchType.EAGER)
     @JoinColumn(name = "result_uid")
+    @SortComparator(QbToolAnswer.QbToolAnswerComparator.class)
     private Set<AssessmentQuestionResult> questionResults = new TreeSet<>();
 
     // *************** NON Persist Fields ********************
Index: lams_tool_lamc/src/java/org/lamsfoundation/lams/tool/mc/model/McUsrAttempt.java
===================================================================
diff -u -r0a5a11351daa8e308190921254096c712ce88837 -r7f09ca6e27d33ac2afa5859c4b482178657748c4
--- lams_tool_lamc/src/java/org/lamsfoundation/lams/tool/mc/model/McUsrAttempt.java	(.../McUsrAttempt.java)	(revision 0a5a11351daa8e308190921254096c712ce88837)
+++ lams_tool_lamc/src/java/org/lamsfoundation/lams/tool/mc/model/McUsrAttempt.java	(.../McUsrAttempt.java)	(revision 7f09ca6e27d33ac2afa5859c4b482178657748c4)
@@ -51,7 +51,7 @@
 @Table(name = "tl_lamc11_usr_attempt")
 //in this entity's table primary key is "uid", but it references "answer_uid" in lams_qb_tool_answer
 @PrimaryKeyJoinColumn(name = "uid")
-public class McUsrAttempt extends QbToolAnswer implements Serializable, Comparable<McUsrAttempt> {
+public class McUsrAttempt extends QbToolAnswer implements Serializable {
     private static final long serialVersionUID = 4514268732673337338L;
 
     @Column(name = "attempt_time")
@@ -184,14 +184,4 @@
 
 	return getMark();
     }
-
-    @Override
-    public int compareTo(McUsrAttempt other) {
-	// if the object does not exist yet, then just return any one of 0, -1, 1. Should not make a difference.
-	if (uid == null) {
-	    return 1;
-	} else {
-	    return (int) (uid.longValue() - other.uid.longValue());
-	}
-    }
 }
\ No newline at end of file