Let R be a relation from the set {1,2,3, …, 60} to itself such that R ={( a, b ): b = pq, where p, q ≥ 3 are prime numbers }. Then, the number of…

Let $\displaystyle R$ be a relation from the set $\displaystyle \{1,2,3, \ldots, 60\}$ to itself such that $\displaystyle \mathrm{R}=\{(\mathrm{a}, \mathrm{b}): \mathrm{b}=\mathrm{pq}$, where $\displaystyle \mathrm{p}, \mathrm{q} \geqslant 3$ are prime numbers $\displaystyle \}$. Then, the number of elements in R is :