Please help me complete this in written relational Algebra

Suppliers (sid: integer, sname: string, address: string Parts (pid: integer. pname: string, color. string) Catalog (sid. integer, pid: integer, cost: real The primary keys are underlined for each table in the database The Catalog relation lists the prices charged for parts by Suppliers. Write the following queries in relational algebra: ).Find the sids of suppliers who supple some red or green part. 2). Find the sids of suppliers who supply every red or green part. 3). Find pairs of sids such that the supplier with the first sid charges more for some part than the supplier with the second sid. ) Find the pids of parts supplied by at least two different suppliers