What is every player's name?
select pname from player
Which of those tried out for the position of striker?
select t1.pname from player as t1 join tryout as t2 on t1.pid = t2.pid where t2.ppos = 'striker'
Of those, who made the team?
select t1.pname from player as t1 join tryout as t2 on t1.pid = t2.pid where t2.decision = 'yes' and t2.ppos = 'striker'