Q41

Consider an Entity-Relationship $(\text{ER})$ model in which entity sets $E_{1}$ and $E_{2}$ are connected by an $m:n$ relationship $R_{12}$. $E_{1}$ and $E_{3}$ are connected by a $1 : n$ ($1$ on the side of $E_{1}$ and $n$ on the side of $E_{3}$) relationship $R_{13}$. $E_{1}$ has two-singled attributes $a_{11}$ and $a_{12}$ of which $a_{11}$ is the key attribute. $E_{2}$ has two singled-valued attributes $a_{21}$ and $a_{22}$ of which $a_{21}$ is the key attribute. $E_{3}$ has two single-valued attributes $a_{31}$ and $a_{32}$ of which $a_{31}$ is the key attribute. The relationships do not have any attributes. If a relational model is derived from the above $\text{ER}$ model, then the minimum number of relations that would be generated if all relation are in $\text{3NF}$ is________________.