GATE | GATE-CS-2015 (Set 1) | Question 65

Consider an Entity-Relationship (ER) model in which entity sets E1 and E2 are connected by an m : n relationship R₁₂, E1 and E3 are connected by a 1 : n (1 on the side of E1 and n on the side of E3) relationship R₁₃. E1 has two single-valued attributes a₁₁ and a₁₂ of which a₁₁ is the key attribute. E2 has two single-valued attributes a₂₁ and a₂₂ is the key attribute. E3 has two single-valued attributes a₃₁ and a₃₂ of which a₃₁ is the key attribute. The relationships do not have any attributes. If a relational model is derived from the above ER model, then the minimum number of relations that would be generated if all the relations are in 3NF is ___________.