What is the most expensive track with Jazz genre?
select max(unitprice) from genre as t1 join track as t2 on t1.genreid = t2.genreid where t1.name = "Jazz"
Show me the average unit price of all Jazz genre tracks.
select avg(unitprice) from genre as t1 join track as t2 on t1.genreid = t2.genreid where t1.name = "Jazz"