You will need to write RA queries to retrieve the required information. The relations given in this exercises are:

Flights (flightNumber, orginalCity, destinationCity, distance, departTime, arrivalTime)

Aircraft (aircraftId, aircraftName, cruisingRange)

Certified (pilotId, aircraftId)

Pilots (pilotId, pilotName, salary)

4. List the aircraft IDs that can be used on non-stop flights from Detroit (DTW) to Beijing (PEK)

Hint: to fly from DTW to PEK non-stop, the aircraft cruising range has to be able to cover the distance from DTW to PEK.

5. Find the IDs of those pilots who make the highest salary.

(b) For the question in 5, write an equivalent RA expression which accomplish the same