How many $\sigma$ and $\pi$ bonds are present in the following?
$(a)$ $But-1-ene-3-yne$
$(b)$ $Buta-1,3-diene$
$(c)$ $CH_2=CH-C\equiv N$
$(d)$ $Propa-1,2-diene$
$(e)$ $1-butyne$ and $2-butane$

(N/A) $CH_2=CH-C\equiv CH$: $7 \sigma$ and $3 \pi$ bonds.
$(b)$ $CH_2=CH-CH=CH_2$: $9 \sigma$ and $2 \pi$ bonds.
$(c)$ $CH_2=CH-C\equiv N$: $6 \sigma$ and $3 \pi$ bonds.
$(d)$ $CH_2=C=CH_2$: $6 \sigma$ and $2 \pi$ bonds.
$(e)$ $1-butyne$ $(CH_3-CH_2-C\equiv CH)$: $10 \sigma$ and $2 \pi$ bonds; $2-butane$ $(CH_3-CH_2-CH_2-CH_3)$: $13 \sigma$ and $0 \pi$ bonds.