diff --git a/README.md b/README.md
index 9c0f157..75d424e 100644
--- a/README.md
+++ b/README.md
@@ -13,6 +13,7 @@ Dateien wie Bilder die zur Lösung einer Aufgabe gehören sind in <br><ins>Medie
 - Vorlesung 7 komplett
 - Vorlesung 8 komplett
 - Vorlesung 9 Aufgabe 2
+- Vorlesung 10 Aufgabe 1
 
 ## Angefangene unfertige Lösungen:
 - Damenproblem: VL 5 Aufgabe 2
diff --git a/src/part10/aufg1/Anwendung.java b/src/part10/aufg1/Anwendung.java
new file mode 100644
index 0000000..0df5607
--- /dev/null
+++ b/src/part10/aufg1/Anwendung.java
@@ -0,0 +1,37 @@
+package part10.aufg1;
+
+import part10.aufg1.Exceptions.*;
+
+public class Anwendung {
+
+    public static void main(String[] args){
+        matrix nr1 = new matrix(2,3);
+        matrix nr2 = new matrix(3,3);
+
+        nr1.setValue(1,1,1);
+        nr2.setValue(0,0,4);
+
+        try{
+            nr2.addMatrix(nr1);
+        }
+        catch (MatrixIncommpatibleForAdditionException e){
+            System.out.println("===========================================");
+            System.out.println("Details: \n" + e.getMessage());
+            System.out.println("===========================================");
+        }
+
+        matrix nr3 = new matrix(2,3);
+        nr3.setRow(new int[]{1,2,3},0);
+        nr3.setRow(new int[]{4,5,6},1);
+
+
+        //matrix nr4 = new matrix(3,2); // works fine
+        matrix nr4 = new matrix(3,3); // causes Runtime Exception
+
+        nr4.setCol(new int[]{7,9,11},0);
+        nr4.setCol(new int[]{8,10,12},1);
+
+
+        System.out.println(nr3.multiplyMatrix(nr4));
+    }
+}
diff --git a/src/part10/aufg1/Exceptions/MatrixIncommpatibleForAdditionException.java b/src/part10/aufg1/Exceptions/MatrixIncommpatibleForAdditionException.java
new file mode 100644
index 0000000..71e3830
--- /dev/null
+++ b/src/part10/aufg1/Exceptions/MatrixIncommpatibleForAdditionException.java
@@ -0,0 +1,8 @@
+package part10.aufg1.Exceptions;
+
+public class MatrixIncommpatibleForAdditionException extends Exception{
+    MatrixIncommpatibleForAdditionException(String s){
+        super(s);
+    }
+}
+
diff --git a/src/part10/aufg1/Exceptions/MatrixIncompatibleForMultiplicationException.java b/src/part10/aufg1/Exceptions/MatrixIncompatibleForMultiplicationException.java
new file mode 100644
index 0000000..ff1da8f
--- /dev/null
+++ b/src/part10/aufg1/Exceptions/MatrixIncompatibleForMultiplicationException.java
@@ -0,0 +1,8 @@
+package part10.aufg1.Exceptions;
+
+
+ class MatrixIncompatibleForMultiplicationException extends RuntimeException{
+    MatrixIncompatibleForMultiplicationException(String s){
+        super(s);
+    }
+ }
\ No newline at end of file
diff --git a/src/part10/aufg1/Exceptions/matrix.java b/src/part10/aufg1/Exceptions/matrix.java
new file mode 100644
index 0000000..0af8e53
--- /dev/null
+++ b/src/part10/aufg1/Exceptions/matrix.java
@@ -0,0 +1,171 @@
+package part10.aufg1.Exceptions;
+
+public class matrix {
+    private int numberOfRows;
+    private int numberOfCols;
+    int[][] field;
+
+    public matrix(int numberOfRows, int numberOfCols){
+        this.numberOfRows = numberOfRows;
+        this.numberOfCols = numberOfCols;
+
+        field = new int[numberOfRows][numberOfCols];
+    }
+
+    public int getNumberOfCols() {
+        return numberOfCols;
+    }
+
+    public int getNumberOfRows() {
+        return numberOfRows;
+    }
+
+    public void print(){
+        for (int i = 0; i<this.numberOfRows; i++){
+            for (int j = 0; j<this.numberOfCols; j++){
+                System.out.print(field[i][j]);
+                if (j != this.numberOfCols - 1) {
+                    System.out.print(" ; ");
+                }
+            }
+            System.out.println();
+        }
+        System.out.println("===========");
+    }
+
+    public void setValue(int row, int col, int value){field[row][col] = value;}
+
+    int getValue(int row, int col){return field[row][col];}
+
+    public int[] getRow(int row){
+        return this.field[row];
+    }
+
+    public void setRow(int[] values, int row) {
+        if (values.length == this.getNumberOfCols()) {
+            for (int i = 0; i < values.length; i++){
+                this.setValue(row,i,values[i]);
+            }
+        }
+    }
+
+    public int[] getCol(int col){
+        int[] result = new int[this.getNumberOfRows()];
+
+        for (int i=0; i<this.getNumberOfRows(); i++){
+            result[i] = this.getValue(i, col);
+        }
+
+        return result;
+    }
+
+    public void setCol(int[] values, int col){
+        if (values.length == this.getNumberOfRows()){
+            for (int i=0; i<values.length; i++){
+                this.setValue(i, col, values[i]);
+            }
+        }
+    }
+
+    public void scalarMultiply(int factor){
+        for (int i = 0; i<this.numberOfRows; i++) {
+            for (int j = 0; j < this.numberOfCols; j++) {
+                field[i][j] *= factor;
+            }
+        }
+    }
+
+    public void addMatrix(matrix matrix2) throws MatrixIncommpatibleForAdditionException {
+            if ((this.getNumberOfRows() == matrix2.getNumberOfRows()) && (this.getNumberOfCols() == matrix2.getNumberOfCols())) {
+                for (int i = 0; i < this.numberOfRows; i++) {
+                    for (int j = 0; j < this.numberOfCols; j++) {
+                        this.field[i][j] += matrix2.field[i][j];
+                    }
+                }
+            } else {
+                throw new MatrixIncommpatibleForAdditionException("Wrong size for addition, matrix1 is " + getNumberOfRows() +
+                                                                "x" + getNumberOfCols() + " and matrix2 is " +
+                                                                matrix2.getNumberOfRows() + "x" + matrix2.getNumberOfCols());
+            }
+        }
+
+    public boolean multiplyMatrix(matrix matrix2) throws MatrixIncompatibleForMultiplicationException {
+        boolean compatible = false;
+
+        if(this.getNumberOfRows() == matrix2.getNumberOfCols()){
+            compatible = true;
+            matrix result = new matrix(this.getNumberOfRows(), matrix2.getNumberOfCols());
+
+            for (int i=0; i<this.field.length; i++){
+                int[] currentRow = this.getRow(i);
+
+                for (int j=0; j<matrix2.field[0].length; j++){
+                    int[] currentCol = matrix2.getCol(j);
+                    int dotProduct = dotProduct(currentRow, currentCol);
+                    result.setValue(i,j,dotProduct);
+                }
+            }
+
+            result.print();
+        }
+        else {
+            throw new MatrixIncompatibleForMultiplicationException("Wrong Sizes");
+        }
+
+        return compatible;
+    }
+
+    private int dotProduct(int[] vector1, int[] vector2){
+        int result = 0;
+
+        if (vector1.length == vector2.length){
+            for (int i=0; i<vector1.length; i++){
+                result += vector1[i] * vector2[i];
+            }
+        }
+        else {
+            // Vectors not compatible Exception
+            // TODO
+        }
+        return result;
+    }
+
+    public static void main(String[] args){
+        matrix nr1 = new matrix(2,3);
+        matrix nr2 = new matrix(3,3);
+
+        nr1.setValue(1,1,1);
+        nr2.setValue(0,0,4);
+
+        try{
+            nr2.addMatrix(nr1);
+        }
+        catch (MatrixIncommpatibleForAdditionException e){
+            System.out.println("===========================================");
+            System.out.println("===========================================");
+            System.out.println("Details: " + e.getMessage());
+        }
+
+
+        nr2.scalarMultiply(8);
+        nr2.print();
+
+        nr2.scalarMultiply(7);
+        nr2.print();
+
+        System.out.println("========================");
+
+        matrix nr3 = new matrix(2,3);
+        nr3.setRow(new int[]{1,2,3},0);
+        nr3.setRow(new int[]{4,5,6},1);
+        nr3.print();
+
+        matrix nr4 = new matrix(3,2);
+        nr4.setCol(new int[]{7,9,11},0);
+        nr4.setCol(new int[]{8,10,12},1);
+        nr4.print();
+
+        System.out.println(nr3.multiplyMatrix(nr4));
+        System.out.println(nr4.multiplyMatrix(nr3));
+    }
+}
diff --git a/src/part10/placeholder.java b/src/part10/placeholder.java
new file mode 100644
index 0000000..86e5a55
--- /dev/null
+++ b/src/part10/placeholder.java
@@ -0,0 +1,7 @@
+package part10;
+
+public class placeholder {
+    public static void main(String[] args){
+        System.out.println("Sup nerd!");
+    }
+}
diff --git a/src/part8/aufg3/matrix.java b/src/part8/aufg3/matrix.java
index 8f33e4c..0e2c462 100644
--- a/src/part8/aufg3/matrix.java
+++ b/src/part8/aufg3/matrix.java
@@ -1,5 +1,10 @@
 package part8.aufg3;
 
+/**
+ * No Exception Handling in this version.
+ * Variante with 'some' is in "part10/aufg1"
+ */
+
 public class matrix {
     private int numberOfRows;
     private int numberOfCols;
@@ -47,10 +52,6 @@ public class matrix {
                 this.setValue(row,i,values[i]);
             }
         }
-        else {
-            //
-            // Amount of given Values is not compatible Exception
-        }
     }
 
     public int[] getCol(int col){
@@ -69,10 +70,6 @@ public class matrix {
                 this.setValue(i, col, values[i]);
             }
         }
-        else {
-            //
-            // Amount of given Values is not compatible Exception
-        }
     }
 
     void scalarMultiply(int factor){
@@ -122,10 +119,7 @@ public class matrix {
                 result += vector1[i] * vector2[i];
             }
         }
-        else {
-            // Vectors not compatible Exception
-            // TODO
-        }
+
         return result;
     }
 
diff --git a/src/part9/Fibonacci.java b/src/part9/Fibonacci.java
new file mode 100644
index 0000000..e17c481
--- /dev/null
+++ b/src/part9/Fibonacci.java
@@ -0,0 +1,55 @@
+package part9;
+//
+// DHBW Stuttgart Campus Horb
+// Vorlesung: Programmierung I 1.Semester
+// Teil 7, Aufgabe 2
+// Musterlösung
+// Autor: Olaf Herden
+//
+
+public class Fibonacci {
+
+    // Methode fiboRekursiv
+	// Berechnet die Fibonacci-Zahl des Arguments n rekursiv
+
+	static long fiboRekursiv(long n){
+
+	  if (n == 1 || n == 2)
+	    {return 1;}
+	  else
+	    {return fiboRekursiv(n-1) + fiboRekursiv(n-2);}
+    }
+
+	// Methode fiboIterativ
+	// Berechnet die Fibonacci-Zahl des Arguments n iterativ
+
+	static long fiboIterativ(long n){
+
+	       long ergebnis =1;
+	       long vorletzter = 1;
+	       long letzter = 1;
+	       if (n == 1 || n == 2)
+	         {return 1;}
+           else
+             {
+              for (int i=3; i<n+1; i++)
+	            {
+	              ergebnis = vorletzter + letzter;
+	              letzter = vorletzter;
+	              vorletzter = ergebnis;
+	            }
+	          return ergebnis;
+	       }
+	}
+
+
+	// Methode main
+	// Aufrufen der beiden Fibonacci-Zahl-Methoden von 1 bis 40
+
+    public static void main(String[]args){
+
+	  for (int i=1;i<=46;i++){
+        System.out.println(i + "  Fibonacci iterativ : " + fiboIterativ(i) + "  Fibonacci rekursiv : " + fiboRekursiv(i));
+      }
+    }
+}
diff --git a/src/part9/aufg3 b/src/part9/aufg3
new file mode 100644
index 0000000..b8fe5e8
--- /dev/null
+++ b/src/part9/aufg3
@@ -0,0 +1,12 @@
+Zur Untersuchung (optischer Aspekte) von Quellcode gibt stehen eine Reihe von Programmen zur Verfügung,
+so z.B. das Programm Checkstyle, das Quelltext auf den Programmierstil überprüft
+und die Regeln der Java COde Conventions beherrscht.
+Laden Sie das Programm Checkstyle herunter, installieren SIe es,
+und überprüfen Sie den obenstehenden Quelltext.
+Sie finden das Programm unter https://checkstyle.org/
+Neben dem eigentlichen Programm gibt es auf der Seite auch Beschreibungen und Hinweise
+über Plugins für gängige IDE.
+
+====================
+
+Auf dem Firmenlaptop ist die Installation nicht erlaubt.
\ No newline at end of file