8)
SELECT CUSTID, COUNT(CUSTID) AS 'NUM_ORD' FROM CUSTOMER GROUP BY CUSTID HAVING COUNT(CUSTID)>=3

9)
SELECT ITEMID, SUM(QTY) AS 'Summary' FROM ITEM GROUP BY ITEMID HAVING ITEMID<=5

10)
SELECT ORDID, AVG(ACTUALPRICE) AS 'Average' FROM ITEM GROUP BY ORDID HAVING ORDID = 615 OR ORDID <608