How many total number of substituents are present in the following compound?

Write the $IUPAC$ names of the following structures:
$(i)$ $CH_3-CH=CH-CH(Br)-CH_3$
$(ii)$ $CH_2=C(CH_3)-CH(Br)-CH_3$
$(iii)$ $CH_3-CH=C(CH_3)-CH(Br)-CH_3$
$(iv)$ $CH_3-C(CH_3)=CH-CH_2Br$
$(v)$ $CH_3-CH=CH-CH_2Br$
$(vi)$ $CH_2=C(CH_3)-CH_2Br$

The $IUPAC$ name of the compound shown below is:

The $IUPAC$ name of the compound having the formula $CH \equiv C-CH=CH_2$ is

Identify the correct $IUPAC$ name of the hydrocarbon $(x)$ containing three primary carbon atoms and with a molar mass of $72 \text{ g mol}^{-1}$.

The $IUPAC$ name of the compound given below is: