Homework2 Suppose we have 3 tables which are Users, Videos and Ratings. Each user has a useriD (primary key) and name. Each video has a videolD(primary key), uploader (UserID ... Foreign key), length(seconds), and title. Each vedio (UserID + VideolD) is given a rating from 1 to 5 . Table 1: Users Table 2: Videos Table 3 : Ratings 1. For the following math expression length4 (Videos Ratings) How many, and which, are the columns of the answer? (1point) How many tuples are in the results? (2 points) Give, as a table, all of the tuples returned by the query. ( 3 points) 3. write math expression for the following query ( 3 points) Query: selects the uploader of all videos under 20 seconds