Joining Select Statements in SQL Server

Hi,

Joining or Combining Select Statements in SQL Server

SELECT * FROM

(SELECT Person, COUNT(*) AS '# Tasks' FROM Table GROUP BY Person) t1 

INNER JOIN

(SELECT Person, COUNT(*) AS '# Late' FROM Table WHERE Age > 30 GROUP BY Person) t2

ON t1.Person= t2.Person

Three Select Statements

SELECT * 
FROM  
 (SELECT Product, SUM(QTY) FROM Table1 GROUP BY ID) K1
       JOIN 
(SELECT Product, SUM(QTY) FROM Table2 GROUP BY ID)  K2 
ON K1.Product = K2.Product
       JOIN 
(SELECT Product, SUM(QTY) FROM Table3 GROUP BY ID) K3
ON K1.Product = K3.Product