Consider the following schema and write the relational algebra:

Sailors(SID,Sname,Rating,Age)

BOATS(BID,Bname,Color)

RESERVE(SID,BID,Day)

1.Retrieve the sailors name who have reserved red and green boats.

2.Retrieve the sailors name with age over 20 years and reserved black boats.

3.Retrieve the sailors name who reserved green boats on Monday.