What is the difference in oxidation number of $Mn$ in $KMnO_4$ and $MnO_2$?

In which of the following compounds is the oxidation number of carbon maximum?

In which of the following molecules or ions does sulphur have the minimum oxidation number?

What are the oxidation states of the two sulfur atoms in thiosulfuric acid $(H_2S_2O_3)$?

One mole of $N_2H_4$ loses $10 \ moles$ of electrons to form a new compound $Z$. Assuming that all the nitrogen atoms appear in the new compound, what is the oxidation state of nitrogen in $Z$? (There is no change in the oxidation state of hydrogen.)

The oxidation number of carbon in $CH_3Cl$ is: