diff --git a/__pycache__/test_find_maximum_binary_tree.cpython-39-pytest-5.4.3.pyc b/__pycache__/test_find_maximum_binary_tree.cpython-39-pytest-5.4.3.pyc
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diff --git a/data_structures_and_algorithms/challenges/find-maximum-binary-tree/18_find_maximum_value.jpg b/data_structures_and_algorithms/challenges/find-maximum-binary-tree/18_find_maximum_value.jpg
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index 0000000..9849e98
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diff --git a/data_structures_and_algorithms/challenges/find-maximum-binary-tree/bst.py b/data_structures_and_algorithms/challenges/find-maximum-binary-tree/bst.py
new file mode 100644
index 0000000..05b3a14
--- /dev/null
+++ b/data_structures_and_algorithms/challenges/find-maximum-binary-tree/bst.py
@@ -0,0 +1,104 @@
+class Node:
+    def __init__(self, val):
+        self.val = val
+        self.right = None
+        self.left = None
+
+    def __repr__(self):
+        return '<Node Val: {}>'.format(self.val)
+
+    def __str__(self):
+        return self.val
+
+
+class BST:
+    def __init__(self, iter=[]):
+        self.root = None
+        if not isinstance(iter, (str, tuple, list)):
+            raise TypeError('It\'s not an iterable type.')
+        for item in iter:
+            self.insert(item)
+
+    def __repr__(self):
+        return '<BST Root: {}>'.format(self.root.val)
+
+    def __str__(self):
+        val = self.root.val
+        return str(val)
+
+    def in_order(self, operation):
+        def _walk(node=None):
+            if node is None:
+                return
+
+            if node.left is not None:
+                _walk(node.left)
+
+            operation(node)
+
+            if node.right is not None:
+                _walk(node.right)
+
+        _walk(self.root)
+
+    def pre_order(self, operation):
+        def _walk(node=None):
+            if node is None:
+                return
+
+            operation(node)
+
+            if node.left is not None:
+                _walk(node.left)
+
+            if node.right is not None:
+                _walk(node.right)
+
+        _walk(self.root)
+
+    def post_order(self, operation):
+        def _walk(node=None):
+            if node is None:
+                return
+
+            if node.left is not None:
+                _walk(node.left)
+
+            if node.right is not None:
+                _walk(node.right)
+
+            operation(node)
+
+        _walk(self.root)
+
+    def insert(self, val):
+        if isinstance(val, Node):
+            node = val
+        else:
+            node = Node(val)
+
+        current = self.root
+
+        if self.root is None:
+            self.root = node
+            return node
+
+        while current:
+            try:
+                if val >= current.val:
+                    if current.right is not None:
+                        current = current.right
+                    else:
+                        current.right = node
+                        break
+
+                elif val < current.val:
+                    if current.left is not None:
+                        current = current.left
+                    else:
+                        current.left = node
+                        break
+            except TypeError:
+                raise TypeError('the value cannot be compared')
+
+        return node
\ No newline at end of file
diff --git a/data_structures_and_algorithms/challenges/find-maximum-binary-tree/find_maximum_binary_tree.py b/data_structures_and_algorithms/challenges/find-maximum-binary-tree/find_maximum_binary_tree.py
new file mode 100644
index 0000000..93c1962
--- /dev/null
+++ b/data_structures_and_algorithms/challenges/find-maximum-binary-tree/find_maximum_binary_tree.py
@@ -0,0 +1,29 @@
+from .bst import BST
+
+
+def find_maximum_value(bst):
+    """ function finding max value from bst input \
+        it checks if input is of BST type \
+        and if root is empty
+    """
+    if not isinstance(bst, BST):
+        raise TypeError('It\'s not a BST type.')
+
+    if bst.root is None:
+        raise ValueError('BST is empty.')
+
+    max = 0
+    this_level = [bst.root]
+
+    while this_level:
+        next_level = list()
+        for n in this_level:
+            if n.val > max:
+                max = n.val
+            if n.left:
+                next_level.append(n.left)
+            if n.right:
+                next_level.append(n.right)
+        this_level = next_level
+
+    return max
\ No newline at end of file
diff --git a/data_structures_and_algorithms/challenges/find-maximum-binary-tree/read.md b/data_structures_and_algorithms/challenges/find-maximum-binary-tree/read.md
new file mode 100644
index 0000000..c9b1833
--- /dev/null
+++ b/data_structures_and_algorithms/challenges/find-maximum-binary-tree/read.md
@@ -0,0 +1,2 @@
+![image](https://github.com/MsDiala/data-structures-and-algorithms-python/blob/find-maximum-binary-tree/data_structures_and_algorithms/challenges/find-maximum-binary-tree/18_find_maximum_value.jpg)
+I got help from prev student in codefelowes 
diff --git a/data_structures_and_algorithms/data_structures/BinaryTree/__pycache__/maximum_binary_tree.cpython-38.pyc b/data_structures_and_algorithms/data_structures/BinaryTree/__pycache__/maximum_binary_tree.cpython-38.pyc
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diff --git a/data_structures_and_algorithms/data_structures/BinaryTree/__pycache__/maximum_binary_tree.cpython-39.pyc b/data_structures_and_algorithms/data_structures/BinaryTree/__pycache__/maximum_binary_tree.cpython-39.pyc
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diff --git a/data_structures_and_algorithms/data_structures/BinaryTree/maximum_binary_tree.py b/data_structures_and_algorithms/data_structures/BinaryTree/maximum_binary_tree.py
new file mode 100644
index 0000000..5ba7dd7
--- /dev/null
+++ b/data_structures_and_algorithms/data_structures/BinaryTree/maximum_binary_tree.py
@@ -0,0 +1,20 @@
+from  data_structures_and_algorithms.data_structures.tree.tree import Ktree
+
+def find_maximum_value(bst):
+    '''Find the maximum balue in a tree'''
+
+    if not isinstance(bst,Ktree):
+        raise TypeError('argument must be of type <BST')
+
+    if not bst.root:
+        return None
+        
+    cur = bst.root.val
+
+    def update(node):
+        nonlocal cur
+        if node.val > cur:
+            cur = node.val
+        
+    bst.pre_order(update)
+    return cur
\ No newline at end of file
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diff --git a/data_structures_and_algorithms/__init__.py b/data_structures_and_algorithms/data_structures/tree/__init__.py
similarity index 100%
rename from data_structures_and_algorithms/__init__.py
rename to data_structures_and_algorithms/data_structures/tree/__init__.py
diff --git a/data_structures_and_algorithms/data_structures/tree/__pycache__/__init__.cpython-38.pyc b/data_structures_and_algorithms/data_structures/tree/__pycache__/__init__.cpython-38.pyc
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index 65e5d35..07dc3d5 100644
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diff --git a/data_structures_and_algorithms/data_structures/tree/__pycache__/tree.cpython-39.pyc b/data_structures_and_algorithms/data_structures/tree/__pycache__/tree.cpython-39.pyc
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diff --git a/data_structures_and_algorithms/data_structures/tree/tree.py b/data_structures_and_algorithms/data_structures/tree/tree.py
index 47cbe49..8aa08d7 100644
--- a/data_structures_and_algorithms/data_structures/tree/tree.py
+++ b/data_structures_and_algorithms/data_structures/tree/tree.py
@@ -1,125 +1,105 @@
-class Node:
-    """Node class definition."""
 
-    def __init__(self, val=None):
-        """Create an instance of Node object."""
+class Node:
+    def __init__(self, val):
         self.val = val
-        self.children = []
-        self._next = next
+        self.right = None
+        self.left = None
 
     def __repr__(self):
-        """Node class representation."""
-        return '<Node Val: {}>'.format(self.val)
+        return self.val
 
     def __str__(self):
-        """Node class string printout."""
-        return 'Node Val: {}'.format(self.val)
+        return self.val
 
-class Queue:
-    def __init__(self, iter=[]):
-        self.front = None
-        self.back = None
-        self._length = 0
-
-        if not isinstance(iter, (list, dict, tuple)):
-            """ check for iterable """
-            raise TypeError('It is not iterable.')
-        for i in iter:
-            self.enqueue(i)
-
-    def enqueue(self, val):
-        """ add a value, increase size by 1"""
-        node = Node(val)
-        if self._length == 0:
-            self.front = self.back = node
-            self._length += 1
-            return node
-        self.back.next = node
-        self.back = node
-        self._length += 1
-        return node
-
-    def dequeue(self):
-        """ remove node from the front of queue """
-        if self._length == 0:
-            raise IndexError('You cannot dequeue() when front is empty')
-
-        temp = self.front
-        self.front = temp.next
-        self._length -= 1
-        return temp
-    
-class KTree:
-    """Ktree class definition."""
 
-    def __init__(self):
-        """Create an instance of KTree object."""
+class Ktree:
+    def __init__(self, iter=[]):
         self.root = None
+        
+        for item in iter:
+            self.insert(item)
 
     def __repr__(self):
-        """Ktree class representation."""
-        return '<KTree Root Val: {}>'.format(self.root.val)
+        return '<BST Root {}>'.format(self.root.val)
 
     def __str__(self):
-        """Ktree class string printout."""
-        return 'KTree Root Val: {}'.format(self.root.val)
+        return self.root.val
 
-    def pre_order(self, operation):
-        """Ktree pre_order traversal."""
+    def in_order(self, operation):
+        """in_order traversal"""
         def _walk(node=None):
             if node is None:
                 return
 
-            operation(node)
+            if node.left is not None:
+                _walk(node.left)
+            operation(node.val)
 
-            for child in node.children:
-                _walk(child)
+            if node.right is not None:
+                _walk(node.right)
 
-        _walk(self.root)
+        if self.root is None:
+            return False
+        else:
+            _walk(self.root)
+    
+    def insert(self, val):
+        node = Node(val)
 
-    def post_order(self, operation):
-        """Ktree post_order traversal."""
+        def _insert(current, node):
+            """isert node in bst"""
+            if node.val >= current.val:
+                if current.right is None:
+                    current.right = node
+                else:
+                    current = current.right
+                    _insert(current, node)
+            if node.val < current.val:
+                if current.left is None:
+                    current.left = node
+                else:
+                    current = current.left
+                    _insert(current, node)
+
+        if self.root is None:
+            self.root = node
+            return node
+        else:
+            current = self.root
+            _insert(current, node)
+
+    def pre_order(self, operation):
+        """preorder traversal"""
         def _walk(node=None):
             if node is None:
                 return
+            operation(node.val)
+
+            if node.left is not None:
+                _walk(node.left)
+
+            if node.right is not None:
+                _walk(node.right)
+        
+        if self.root is None:
+            return False
+        else:
+            _walk(self.root)
+    
+    def post_order(self, operation):
+        """postorder traversal"""
+        def _walk(node=None):
+            if node.left is not None:
+                _walk(node.left)
 
-            for child in node.children:
-                _walk(child)
-
-            operation(node)
-
-        _walk(self.root)
-
-    def breadth_first_traversal(self, operation):
-        """Ktree breadth_first_traversal."""
-        queue = Queue()
-        queue.enqueue(self.root)
-        while queue._length > 0:
-            current = queue.dequeue()
-            operation(current)
-            for child in current.children:
-                queue.enqueue(child)
-
-    def insert(self, val, parent=None):
-        """Insert a value at first instance of given parent."""
-        if parent is None:
-            if self.root is None:
-                self.root = Node(val)
-                return self.root
-            raise ValueError('parent node is none.')
-
-        node = Node(val)
-
-        def _walk(curr=None):
-            if curr is None:
-                return
+            if node.right is not None:
+                _walk(node.right)
+            operation(node.val)
 
-            if curr.val == parent:
-                curr.children.append(node)
+            if node is None:
                 return
-
-            for child in curr.children:
-                _walk(child)
-                if node in child.children:
-                    return
-        _walk(self.root)
\ No newline at end of file
+        
+        if self.root is None:
+            return False
+        else:
+            _walk(self.root)
\ No newline at end of file
diff --git a/test_find_maximum_binary_tree.py b/test_find_maximum_binary_tree.py
new file mode 100644
index 0000000..46d4948
--- /dev/null
+++ b/test_find_maximum_binary_tree.py
@@ -0,0 +1,27 @@
+import pytest
+from .find_maximum_value_binary_tree import find_maximum_value
+from .bst import BST
+
+
+def test_typeerror_true():
+    """ test on input type """
+    with pytest.raises(TypeError):
+        find_maximum_value([1, 2, 3])
+
+
+def test_maximum_five(five_element_bst):
+    """ test for finding max from bst with five nodes. """
+    b = find_maximum_value(five_element_bst)
+    assert b == 9
+
+
+def test_maximum_seven(seven_element_bst):
+    """ test for finding max from bst with seven nodes. """
+    b = find_maximum_value(seven_element_bst)
+    assert b == 30
+
+
+def test_empty():
+    """ test for empty BST input """
+    with pytest.raises(ValueError):
+        find_maximum_value(BST())
\ No newline at end of file
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diff --git a/tests/data_structures/__pycache__/test_tree.cpython-39-pytest-5.4.3.pyc b/tests/data_structures/__pycache__/test_tree.cpython-39-pytest-5.4.3.pyc
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diff --git a/tests/data_structures/test_maximum_binary_tree.py b/tests/data_structures/test_maximum_binary_tree.py
new file mode 100644
index 0000000..9d851f8
--- /dev/null
+++ b/tests/data_structures/test_maximum_binary_tree.py
@@ -0,0 +1,22 @@
+import pytest
+from data_structures_and_algorithms.data_structures.tree.tree import Ktree
+from data_structures_and_algorithms.data_structures.BinaryTree.maximum_binary_tree  import find_maximum_value
+
+def test_invalid_arg():
+    '''Test invalid parameter'''
+    with pytest.raises(TypeError):
+        find_maximum_value(4)
+
+def test_empty_Ktree():
+    '''Test an empty Ktree has no max value'''
+    assert find_maximum_value(Ktree()) is None
+
+def test_single_Ktree():
+    '''Test single valued Ktree'''
+    assert find_maximum_value(Ktree([1])) == 1
+
+def test_multi_Ktree():
+    '''Test multi-valued non-balanced Ktree'''
+    l = [5,2,15,33,1,8,7,4,2,66,5,1,0,-2]
+    b = Ktree(l)
+    assert find_maximum_value(b) == 66
\ No newline at end of file
diff --git a/tests/data_structures/test_tree.py b/tests/data_structures/test_tree.py
index bb66f80..21c5b9c 100644
--- a/tests/data_structures/test_tree.py
+++ b/tests/data_structures/test_tree.py
@@ -1,51 +1,87 @@
+  
 import pytest
-from data_structures_and_algorithms.data_structures.tree.tree import Node 
+from data_structures_and_algorithms.data_structures.tree.tree import Ktree 
+from data_structures_and_algorithms.data_structures.tree.tree import Node as nd
 
 
-def test_insert_small_ktree(small_tree):
-    """This checks if a value inserted correctly."""
-    # import pdb; pdb.set_trace()
-    small_tree.insert(11, 3)
-    assert small_tree.root.children[1].children[0].val == 11
+@pytest.fixture
+def empty_Ktree():
+    """make empty Ktree"""
+    return Ktree()
 
 
-def test_insert_small_ktree_no_parent(small_tree):
-    """This tests if ValueError is raised when passing no parent."""
-    with pytest.raises(ValueError):
-        small_tree.insert(8)
+@pytest.fixture
+def node():
+    """make node"""
+    return nd(5)
+ 
 
+@pytest.fixture
+def small_Ktree():
+    return Ktree([4, 3, 3.5, 2, 5, 6, 7])
 
-def test_pre_order_traverse(small_tree):
-    """Confirm pre_order traversal."""
-    ls = []
-    small_tree.pre_order(lambda n: ls.append(n.val))
-    assert ls == [5, 9, 3]
 
+def test_constractor(empty_Ktree):
+    """test constarctor"""
+    assert empty_Ktree.root is None
 
-def test_post_order_traversal(small_tree):
-    """Confirm post_order traversal."""
-    ls = []
-    small_tree.post_order(lambda n: ls.append(n.val))
-    assert ls == [9, 3, 5]
 
+def test_node(node):
+    """test node object"""
+    assert node.right is None
+    assert node.left is None
 
-def test_breadth_first_traversal(small_tree):
-    """Confirm breadth_first_traversal."""
-    ls = []
-    small_tree.breadth_first_traversal(lambda n: ls.append(n.val))
-    assert ls == [5, 9, 3]
 
+def test_value_of_node(node):
+    """test repr and str of node"""
+    assert node.val == 5
 
-def test_ktree_node():
-    """Test if K-tree node is made properly."""
-    nd = Node(34)
-    assert nd.val == 34
-    assert nd.children == []
-    assert repr(nd) == '<Node Val: 34>'
-    assert str(nd) == 'Node Val: 34'
 
+def test_insert_empty(empty_Ktree):
+    """insert in empty Ktree"""
+    empty_Ktree.insert(5)
+    assert empty_Ktree.root.val == 5
 
-def test_ktree(small_tree):
-    """Test K-tree str and repr."""
-    assert repr(small_tree) == '<KTree Root Val: 5>'
-    assert str(small_tree) == 'KTree Root Val: 5'
\ No newline at end of file
+
+def test_insert_empty_two(empty_Ktree):
+    """insert two items"""
+    empty_Ktree.insert(3)
+    empty_Ktree.insert(10)
+    assert empty_Ktree.root.val == 3
+    assert empty_Ktree.root.right.val == 10
+    assert empty_Ktree.root.left is None
+
+
+def test_repr_small_Ktree(small_Ktree):
+    """test repr of small Ktree"""
+    assert small_Ktree.root.val == 4
+    assert small_Ktree.root.right.val == 5
+
+
+def test_insert_for_small_Ktree(small_Ktree):
+    """test insert in small Ktree"""
+    small_Ktree.insert(1)
+    small_Ktree.insert(1.5)
+    assert small_Ktree.root.left.val == 3
+    assert small_Ktree.root.right.val == 5
+
+
+def test_inorder_traverse(small_Ktree):
+    """test in order tarversal"""
+    a = []
+    small_Ktree.in_order(a.append)
+    assert a == [2, 3, 3.5, 4, 5, 6, 7]
+
+
+def test_pre_order(small_Ktree):
+    """test preorder traversal"""
+    a = []
+    small_Ktree.pre_order(a.append)
+    assert a == [4, 3, 2, 3.5, 5, 6, 7]
+
+
+def test_post_order(small_Ktree):
+    """test preorder"""
+    a = []
+    small_Ktree.post_order(a.append)
+    assert a == [2, 3.5, 3, 7, 6, 5, 4]
\ No newline at end of file