Answer the following questions (250 words max/question). a. Explain the concept of program-data independence, and explain how it is achieved in the database approach.

b. Briefly contrast and compare the following development approaches:

the systems development life cycle and the prototyping methodology.

c. Discuss the difference between entity type and entity instance.

Question 2 Give a simple example of an E-R diagram for each of the following concepts:

a. Associative entity

b. Weak entity

c. Unary relationship