Which of the following statements is not correct about order of a reaction?

order of a reaction : order of a reaction is equal to the sum of powers of concentration of the reactants in rate law expression.
For any chemical reaction, $\mathrm{xA}+\mathrm{yB}⟶ \mathrm{Product}$
$\text{ Rate }=\mathrm{k}\left[\mathrm{A}{]}^{\mathrm{x}}\right[\mathrm{B}{]}^{\mathrm{y}}\text{ and Order }=\mathrm{x}+\mathrm{y}$
Order of a reaction can be a fraction also. It is not always equal to sum of the stoichiometric coefficients of reactants in the balanced chemical equation. For a reaction, it may or may not be equal to sum of stoichiometric coefficient of reactants.