diff --git a/Problem1_ConsecutiveNumbers.sql b/Problem1_ConsecutiveNumbers.sql
new file mode 100644
index 0000000..466a1da
--- /dev/null
+++ b/Problem1_ConsecutiveNumbers.sql
@@ -0,0 +1,7 @@
+# Write your MySQL query statement below
+select distinct l1.num as ConsecutiveNums
+from Logs l1, logs l2, logs l3
+where l1.id+1=l2.id
+and l2.id+1=l3.id
+and l1.num=l2.num
+and l2.num=l3.num
\ No newline at end of file
diff --git a/Problem2_PassengerInBus.sql b/Problem2_PassengerInBus.sql
new file mode 100644
index 0000000..52f3e18
--- /dev/null
+++ b/Problem2_PassengerInBus.sql
@@ -0,0 +1,13 @@
+# Write your MySQL query statement below
+with cte as(
+select 
+p.passenger_id,p.arrival_time,min(b.arrival_time) as btime
+from passengers p 
+inner join buses b on p.arrival_time <= b.arrival_time
+group by 1)
+
+select b.bus_id,count(c.passenger_id) as passengers_cnt
+from buses b 
+left join cte c on b.arrival_time=c.btime
+group by 1
+order by 1
\ No newline at end of file
diff --git a/Problem3_UserActivity.sql b/Problem3_UserActivity.sql
new file mode 100644
index 0000000..fac0993
--- /dev/null
+++ b/Problem3_UserActivity.sql
@@ -0,0 +1,6 @@
+# Write your MySQL query statement below
+select activity_date as day,count(distinct user_id) as active_users
+from activity
+where  datediff('2019-07-27',activity_date) between 0 and 29
+group by 1
+having count(distinct user_id) >0
\ No newline at end of file
diff --git a/Problem4_DynamicPivoting.sql b/Problem4_DynamicPivoting.sql
new file mode 100644
index 0000000..2db591b
--- /dev/null
+++ b/Problem4_DynamicPivoting.sql
@@ -0,0 +1,20 @@
+CREATE PROCEDURE PivotProducts()
+BEGIN
+-- 	select product_id,
+--     sum(if(store='LC_Store',price,null)) as 'LC_Store',
+--     sum(if(store='Nozama',price,null)) as 'Nozama',
+--     sum(if(store='Shop',price,null)) as 'Shop',
+--     sum(if(store='Souq',price,null)) as 'Souq'
+--     from products
+--     group by 1;
+set session group_concat_Max_len=1000000;
+    select
+    group_concat(distinct(concat('sum(if(store="',store,'",price,null)) as ',store)))
+    into @sql from products;
+
+    set @sql=concat('select product_id,',@sql,' from products group by 1');
+    
+    prepare statement from @sql;
+    execute statement;
+    deallocate prepare statement;
+END