diff --git a/data_structures/binary_tree/treap.py b/data_structures/binary_tree/treap.py
index 3114c6fa1c26..3c1927701947 100644
--- a/data_structures/binary_tree/treap.py
+++ b/data_structures/binary_tree/treap.py
@@ -41,7 +41,7 @@ def split(root: Node | None, value: int) -> tuple[Node | None, Node | None]:
     """
     if root is None or root.value is None:  # None tree is split into 2 Nones
         return None, None
-    elif value < root.value:
+    elif value <= root.value:
         """
         Right tree's root will be current node.
         Now we split(with the same value) current node's left son
@@ -106,16 +106,16 @@ def erase(root: Node | None, value: int) -> Node | None:
     return merge(left, right)
 
 
-def inorder(root: Node | None) -> None:
+def inorder(root: Node | None) -> str:
     """
-    Just recursive print of a tree
+    Returns a comma-separated string of tree values in sorted order.
+
+        >>> inorder(None)
+        ''
     """
-    if not root:  # None
-        return
-    else:
-        inorder(root.left)
-        print(root.value, end=",")
-        inorder(root.right)
+    if root is None:
+        return ""
+    return inorder(root.left) + str(root.value) + "," + inorder(root.right)
 
 
 def interact_treap(root: Node | None, args: str) -> Node | None:
@@ -126,19 +126,19 @@ def interact_treap(root: Node | None, args: str) -> Node | None:
 
         >>> root = interact_treap(None, "+1")
         >>> inorder(root)
-        1,
+        '1,'
         >>> root = interact_treap(root, "+3 +5 +17 +19 +2 +16 +4 +0")
         >>> inorder(root)
-        0,1,2,3,4,5,16,17,19,
+        '0,1,2,3,4,5,16,17,19,'
         >>> root = interact_treap(root, "+4 +4 +4")
         >>> inorder(root)
-        0,1,2,3,4,4,4,4,5,16,17,19,
+        '0,1,2,3,4,4,4,4,5,16,17,19,'
         >>> root = interact_treap(root, "-0")
         >>> inorder(root)
-        1,2,3,4,4,4,4,5,16,17,19,
+        '1,2,3,4,4,4,4,5,16,17,19,'
         >>> root = interact_treap(root, "-4")
         >>> inorder(root)
-        1,2,3,5,16,17,19,
+        '1,2,3,5,16,17,19,'
         >>> root = interact_treap(root, "=0")
         Unknown command
     """
diff --git a/matrix/inverse_of_matrix.py b/matrix/inverse_of_matrix.py
index e53d90df8253..60ccbcefc14b 100644
--- a/matrix/inverse_of_matrix.py
+++ b/matrix/inverse_of_matrix.py
@@ -31,7 +31,7 @@ def inverse_of_matrix(matrix: list[list[float]]) -> list[list[float]]:
 
     Doctests for 3x3
     >>> inverse_of_matrix([[2, 5, 7], [2, 0, 1], [1, 2, 3]])
-    [[2.0, 5.0, -4.0], [1.0, 1.0, -1.0], [-5.0, -12.0, 10.0]]
+    [[2.0, 1.0, -5.0], [5.0, 1.0, -12.0], [-4.0, -1.0, 10.0]]
     >>> inverse_of_matrix([[1, 2, 2], [1, 2, 2], [3, 2, -1]])
     Traceback (most recent call last):
         ...
@@ -145,7 +145,7 @@ def inverse_of_matrix(matrix: list[list[float]]) -> list[list[float]]:
                 adjoint_matrix[i][j] = cofactor_matrix[j][i]
 
         # Inverse of the matrix using the formula (1/determinant) * adjoint matrix
-        inverse_matrix = array(cofactor_matrix)
+        inverse_matrix = array(adjoint_matrix)
         for i in range(3):
             for j in range(3):
                 inverse_matrix[i][j] /= d(determinant)