What is the oxidation state of $Mn$ in $MnO_4^{-}$?

Oxidation number of osmium $(Os)$ in $OsO_4$ is

In alkaline condition,$KMnO_4$ reacts as $2KMnO_4 + 2KOH \to 2K_2MnO_4 + H_2O + [O]$. The equivalent weight of $KMnO_4$ would be (Atomic mass of $K = 39$,$Mn = 55$,$O = 16$).

Consider the following compounds:
$\underline{K}O_2$,$H_2\underline{O}_2$ and $H_2\underline{S}O_4$.
The oxidation states of the underlined elements in them are,respectively,

Oxidation number of $N$ in $HNO_3$ is

Sulphur has the lowest oxidation number in