please help with this $,$ and dont just copy from chatgbt $.$ Question $1$: $40$ Marks

Consider the following subsets of $R$ :

$($a$)S=\{\frac{1}{z}$:zin$\frac{Z}{\frac{?}{?}}\{0\}\}$

$($b$)T=\{2^n$:ninN$\}$

$($c$)U=\{xinR$:$x<mn\; id="EditorElement\_897469">3</mn><mi\; id="EditorElement\_897471">\}</mi>$

$($d$)$ divides $24$