$($b$)$ Consider the following ER diagram,

$($i$)$ specify the condition$($s$)$ that is $($are$)$ necessary in order to represent all

three sets with a single table.

$(2$ marks$)$

$($ii$)$ specify the condition$($s$)$ that is $($are$)$ necessary in order to represent all

three sets with two tables, one for B and one for C$.$

$(2$ marks$)$

$($c$)$ Explain TWO $(2)$ conditions must be met before an entity can be classified as

a weak entity. Give an example of a weak entity.

$(4$ marks$)$

$($d$)$ What is derived attribute? Why derived attribute should be avoided during the

process of creating attributes in logical design?

$(4$ marks$)$