Find Those who’ve hired a red AND Green boat SELECT S.sid FROM Sailors AS S, Boats AS B, Reservations AS R WHERE S.sid=R.sid AND R.bid=B.bid AND (B.colour=‘red’ AND B.colour=‘green’) OR SELECT S.sid FROM Sailors AS S, Boats AS B, Reservations AS R WHERE S.sid=R.sid AND R.bid=B.bid AND B.colour=‘red’ INTERSECT SELECT S.sid FROM Sailors AS S, Boats AS B, Reservations AS R WHERE S.sid=R.sid AND R.bid=B.bid AND B.colour=‘green’