The number of electrons to balance the following equation, ${\mathrm{NO}}_3{}^{-}+4{\mathrm{H}}^{+}+{\mathrm{e}}^{-}⟶{\mathrm{H}}_2\mathrm{O}+\mathrm{NO}$

In the given reaction nitrogen undergo reduction where the oxidation state of nitrogen in ${\mathrm{NO}}_3^{-}$is $+5$ and in $\mathrm{NO}+2$, the change in number of electrons is $+3$. So the required number of electrons to balance the equation is $3$