Confused about cardinality of ER diagram which one is whose cardinality ,look on my notes and clear it out.

Question

Answer 1

please see next page in comment also,

Comments

i hope you got it  .

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I got it but I am unable to do question Gate cse 2018 using this concept.

https://gateoverflow.in/204085/gate-cse-2018-question-11

“he cardinality of E1 is greater than that of E2.”

this line is very confusing ,I did not got anyone’s explanation.

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in general cardinality of any set means number of elements or entities present in it.

ex-    set S={1,2,3,4,5,8,44}  here cardinality of S = number of elements in S that is 7.

so by the statement “ The cardinality of E1 is greater than cardinality of E2” they meant that number of entities in E1 is more than number of entities in E2.      

They also mentioned it is a many-to-one relationship from entity set E1 to entity set E2 and  E1 and E2 participate totally.

which means Many entities of E1 is associated with 1 entity of E2. also due to total participation all entities of both sets are participating in relationship.

so

option A).Every entity in E1 is associated with exactly one entity in E2 is correct answer.

i hope you got it and if not kindly ask again i will explain it by doing it in copy again.

Thank you.

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thankyou ,it is a good explanation.