What is the oxidation number of phosphorus in calcium phosphate?

For a reaction, $\mathrm{NH}_4 \mathrm{NO}_2 \longrightarrow \mathrm{~N}_2+2 \mathrm{H}_2 \mathrm{O}$. Which from following phenomena is true regarding nitrogen?

Identify correct statement for reaction stated below.

$$ \mathrm{Ag}_2 \mathrm{O}+\mathrm{H}_2 \mathrm{O}+2 \mathrm{e}^{-} \longrightarrow 2 \mathrm{Ag}+2 \mathrm{OH}^{-} $$

A compound of Xe and F is found to have atomic ratio $\mathrm{Xe}: \mathrm{F}$ as $0.4: 2.4$, Find the oxidation number of Xe ?