What are the player ids of all students who made the team?
select t1.pid from player as t1 join tryout as t2 on t1.pid = t2.pid where t2.decision = 'yes'
What is the maximum number of hours they spent practicing?
select max(t1.hs) from player as t1 join tryout as t2 on t1.pid = t2.pid where t2.decision = 'yes'
What was the average?
select avg(t1.hs), max(t1.hs) from player as t1 join tryout as t2 on t1.pid = t2.pid where t2.decision = 'yes'