Relational DB, Database Management System

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Suppose R is a relation with attributes A1, A2,..., An. As a function of n, tell how many superkeys R has, if:
1.1 The only key is A1.
1.2 The only key is A1 and A2.
1.3 The only key is {A1 A2} and {A3 , A4}.
1.4 The only key is {A1 A2} and {A1 , A3}.

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