diff --git a/Problem 2 BigCountries.py b/Problem 2 BigCountries.py
new file mode 100644
index 0000000..25a3b94
--- /dev/null
+++ b/Problem 2 BigCountries.py	
@@ -0,0 +1,5 @@
+import pandas as pd
+
+def big_countries(world: pd.DataFrame) -> pd.DataFrame:
+    df = world[(world['area']>=3000000) | (world['population']>=25000000)]
+    return df[['name','population','area']]
\ No newline at end of file
diff --git a/Problem 3 Recyclable and Low Fat Products.py b/Problem 3 Recyclable and Low Fat Products.py
new file mode 100644
index 0000000..77d7111
--- /dev/null
+++ b/Problem 3 Recyclable and Low Fat Products.py	
@@ -0,0 +1,4 @@
+import pandas as pd
+
+def find_products(products: pd.DataFrame) -> pd.DataFrame:
+    return products[(products['low_fats']=='Y') & (products['recyclable']=='Y')][['product_id']]
\ No newline at end of file
diff --git a/Problem 4 Customer Who Never Order.py b/Problem 4 Customer Who Never Order.py
new file mode 100644
index 0000000..5527024
--- /dev/null
+++ b/Problem 4 Customer Who Never Order.py	
@@ -0,0 +1,5 @@
+import pandas as pd
+
+def find_customers(customers: pd.DataFrame, orders: pd.DataFrame) -> pd.DataFrame:
+    return customers[~customers['id'].isin(orders['customerId'])][['name']].rename(columns ={'name':'Customers'})
+    
\ No newline at end of file
diff --git a/README.md b/README.md
index a51355c..a781f87 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
 # Pandas1
 
-1 Problem 1 : Make a Pandas DataFrame with two-dimensional list	(	https://www.geeksforgeeks.org/make-a-pandas-dataframe-with-two-dimensional-list-python/)
+1 Problem 1 : Make a Pandas DataFrame with two-dimensional list	(	https://www.geeksfor    geeks.org/make-a-pandas-dataframe-with-two-dimensional-list-python/)
 
 2 Problem 2 :Big Countries	(	https://leetcode.com/problems/big-countries/ )