Completed first 3 problems Sql3

Problem1.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 = l2.id - 1
+AND l2.id = l3.id - 1
+AND l1.num = l2.num
+AND l2.num = l3.num;

Problem2.sql

@@ -0,0 +1,14 @@
+# 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 passenger_id
+)
+SELECT b.bus_id, COUNT(c.btime) AS 'passengers_cnt'
+FROM Buses b
+LEFT JOIN CTE c
+ON c.btime = b.arrival_time
+GROUP BY b.bus_id
+ORDER BY b.bus_id;

Problem3.sql

@@ -0,0 +1,5 @@
+# Write your MySQL query statement below
+SELECT activity_date AS 'day', COUNT(DISTINCT user_id) AS 'active_users'
+FROM Activity
+WHERE activity_date >= '2019-06-28' AND activity_date <= '2019-07-27'
+GROUP BY activity_date;