Use only one table in each select statement

Table definitions

team (tid,name,city,conference)

player(pid,pfname,plname,pos,ht,wt,college)

plays(tid,pid,season,salary)

coach(cid,cfname,clname)

coaches(tid,cid,season)

List each player name and the team they play for.

List the coach for each player, list only the first 50 players, just list the last names.

What is the average player weight for each team?