Write $IUPAC$ names of the following compounds:
$(i)$ $[CH_3]_3 C CH_2 C(CH_3)_3$
$(ii)$ $[CH_3]_2 C(C_2 H_5)_2$
$(iii)$ tetra$-tert-$butylmethane

(N/A) $(i)$ The longest chain contains $5$ carbon atoms. The parent alkane is pentane. Substituents are at positions $2, 2, 4, 4$. The name is $2,2,4,4-$Tetramethylpentane.
$(ii)$ The longest chain contains $5$ carbon atoms. The parent alkane is pentane. Substituents are at position $3, 3$. The name is $3,3-$Dimethylpentane.
$(iii)$ The structure is $C[C(CH_3)_3]_4$. The longest chain contains $9$ carbon atoms. The name is $3,3,7,7-$Tetramethyl$-5,5-$bis$(1,1-$dimethylethyl$)$nonane,commonly referred to as $3,3,5,5-$tetra$-tert-$butylpentane or based on the parent chain $2,2,4,4,8,8,10,10-$octamethyl$-6-(1,1-$dimethylethyl$)$undecane. However,the standard $IUPAC$ name for tetra$-tert-$butylmethane is $3,3,5,5-$tetra$-tert-$butylpentane.