Sql/ PL/SQL Practices

1. You are evaluating a procedure that has the function MOD(100,10). What would be the result ?
A. 10000
B. 10
C. 100
D. 0
E. 1000

2. ) There are four categories of SQL operations.
What is the category for operations that include   REVOKE, ALTER USER and GRANT ?

A. DCL (Data Control Language)
B. DDL (Data Definition Language)
C. DML (Data Manipulation Language)

3.) To Retrive ALTERNATE records from a table.
(EVEN NUMBERED)
select * from employees where rowid in (select decode(mod(rownum,2),0,rowid, null)
 from employees);