Method is block of PL/SQL code used to encapsulate the data access method for an object, it is also specified as part of the abstract datatype specification as (CREATE OR REPLACE TYPE MARKS_TY AS OBJECT) and their body declaration as (CREATE OR REPLACE TYPE BODY MARKS_TY AS MEMBER FUNCTION TOTMARKS()). Before to learn methods it is recommanded to get overview the abstract datatype teqniques. Creating specification CREATE OR REPLACE TYPE MARKS_TY AS OBJECT (M1 NUMBER(3), M2 NUMBER(3), M3 NUMBER(3), MEMBER FUNCTION TOTMARKS(M1 IN NUMBER, M2 IN NUMBER, M3 IN NUMBER) RETURN NUMBER); In above example, TOTMARKS is declaration of function which will be used later in function calling to get defined. Defining function (body declaration) CREATE OR REPLACE TYPE BODY MARKS_TY AS MEMBER FUNCTION TOTMARKS(M1 NUMBER, M2 NUMBER, M3 NUMBER) RETURN NUMBER IS BEGIN RETURN(M1+M2+M3); END; END; / Creating table using above abstract datatyp...