ANSWER HAS TO BE IN RELATIONAL ALGEBRA, NOT SQL

Exercise 2 (Relational Algebra) (25 points] Consider the following relations for an online flight booking system. The primary keys are underlined. All attributes are of type string if not indicated otherwise. (Hint: Use multi-step/multi- line queries to ease the formulation of queries. Use the rename operator p to give intermediate query results a name.] Company (company_ID, company_name, location) Flight (company_ID, flight_number, destination, price: integer, number_of_seats: integer) o A company usually has several flight airlines. Book (company_ID, flight_number, customer_ID, date) Customer (customer ID, name, address) 1. [4 points] Find the names of customers who have booked flights at every company in the US. 2. [3 points) Find the names of customers who never booked a flight. 3. [6 points] Find the names of customers who booked the flight to New York more than once. 4. [4 points] Find the names of the companies that have the biggest (in terms of the number of seats) airplane. 5. [4 points] Find the names of customers who booked flights to Boston and Seattle. 6. [4 points] Find all destinations (unequal to Gainesville) of cheap flights (