diff --git a/BigCountries b/BigCountries
new file mode 100644
index 0000000..d159deb
--- /dev/null
+++ b/BigCountries
@@ -0,0 +1,2 @@
+SELECT name, population, area FROM World
+WHERE area >=3000000 OR population >= 25000000
diff --git a/Problem2_NthHighestSalary.Sql b/Problem2_NthHighestSalary.Sql
new file mode 100644
index 0000000..6a52461
--- /dev/null
+++ b/Problem2_NthHighestSalary.Sql
@@ -0,0 +1,13 @@
+CREATE FUNCTION getNthHighestSalary(N INT) RETURNS INT
+BEGIN
+  RETURN (
+      # Write your MySQL query statement below.
+WITH CTE AS(
+    SELECT *, DENSE_RANK() OVER (Order By Salary desc) AS Rnk FROM Employee
+    )
+
+    SELECT DISTINCT IFNULL(salary, null) FROM CTE
+    WHERE Rnk = N
+
+  );
+END
\ No newline at end of file
diff --git a/Problem3_DeleteDuplicateEmails.sql b/Problem3_DeleteDuplicateEmails.sql
new file mode 100644
index 0000000..b557a26
--- /dev/null
+++ b/Problem3_DeleteDuplicateEmails.sql
@@ -0,0 +1,6 @@
+# Write your MySQL query statement below
+DELETE FROM Person
+WHERE id IN(
+    SELECT id FROM
+    (SELECT *, ROW_NUMBER() OVER(PARTITION BY email ORDER BY id) AS Instances FROM Person )p
+    WHERE p.Instances>1)
\ No newline at end of file