diff --git a/1st problem.sql b/1st problem.sql
new file mode 100644
index 0000000..5636742
--- /dev/null
+++ b/1st problem.sql	
@@ -0,0 +1,32 @@
+# Write your MySQL query statement below
+
+with seniors as 
+(
+select employee_id,
+70000 - rolling_sum as budget_left
+from
+(select *,
+sum(salary) over(order by salary asc) as rolling_sum
+from Candidates
+where experience = 'Senior') a
+where rolling_sum <= 70000
+),
+
+juniors as 
+(
+select a.employee_id
+from
+(select *,
+sum(salary) over(order by salary asc) as rolling_sum
+from Candidates
+where experience = 'Junior') a
+where rolling_sum <= (select coalesce(min(budget_left), 70000) from seniors)
+)
+
+select 'Senior' as experience,
+coalesce(count(employee_id), 0) as accepted_candidates
+from seniors
+union all
+select 'Junior' as experience,
+coalesce(count(employee_id), 0) as accepted_candidates
+from juniors
\ No newline at end of file
diff --git a/2nd problem.sql b/2nd problem.sql
new file mode 100644
index 0000000..b08aacc
--- /dev/null
+++ b/2nd problem.sql	
@@ -0,0 +1,12 @@
+select
+    team_name, count(*) as matches_played, sum(case when home > away then 3 when home = away then 1 else 0 end) as points, sum(home) as goal_for
+    , sum(away) as goal_against, sum(home) - sum(away) as goal_diff
+    
+from 
+    (select home_team_id, home_team_goals as home, away_team_goals as away from matches
+     union all
+     select away_team_id as home_team_id, away_team_goals as home, home_team_goals as away from matches
+	 ) g
+join teams t on g.home_team_id = t.team_id
+group by 1
+order by 3 desc, 6 desc, 1
\ No newline at end of file
diff --git a/3rd problem.sql b/3rd problem.sql
new file mode 100644
index 0000000..957598c
--- /dev/null
+++ b/3rd problem.sql	
@@ -0,0 +1,4 @@
+select salesperson.name
+from orders o join company c on (o.com_id = c.com_id and c.name = 'RED')
+right join salesperson on salesperson.sales_id = o.sales_id
+where o.sales_id is null
\ No newline at end of file
diff --git a/4th problem.sql b/4th problem.sql
new file mode 100644
index 0000000..2c132da
--- /dev/null
+++ b/4th problem.sql	
@@ -0,0 +1,17 @@
+WITH all_ids AS (
+    SELECT ra.requester_id AS id, COUNT(*) AS cnt
+    FROM RequestAccepted ra
+    GROUP BY ra.requester_id
+
+    UNION ALL 
+
+    SELECT ra.accepter_id AS id, COUNT(*) AS cnt 
+    FROM RequestAccepted ra
+    GROUP BY ra.accepter_id
+)
+
+SELECT id, SUM(cnt) AS num
+FROM all_ids
+GROUP BY id
+ORDER BY num DESC
+LIMIT 1