diff --git a/Week03/sequences_first_last.py b/Week03/sequences_first_last.py
new file mode 100644
index 00000000..be02fc43
--- /dev/null
+++ b/Week03/sequences_first_last.py
@@ -0,0 +1,34 @@
+def remove_duplicates(seq: list) -> list:
+    """
+    This function removes duplicates from a list.
+    """
+    result = []
+    for item in seq:
+        if item not in result:
+            result.append(item)
+    return result
+
+
+def list_counts(seq: list) -> dict:
+    """
+    This function counts the number of
+    occurrences of each item in a list.
+    """
+    counts = {}
+    for item in seq:
+        if item in counts:
+            counts[item] += 1
+        else:
+            counts[item] = 1
+    return counts
+
+
+def reverse_dict(d: dict) -> dict:
+    """
+    This function reverses the keys
+    and values of a dictionary.
+    """
+    reversed_dict = {}
+    for key, value in d.items():
+        reversed_dict[value] = key
+    return reversed_dict