# Two oxides of a metal contain 50% and 40% of metal M respectively.If the formula of first oxide is MO,+ve formula of $2^{nd}$ oxide will be

$\begin{array}{1 1}(a)\;MO_2&(b)\;M_2O_3\\(c)\;M_2O&(d)\;M_2O_5\end{array}$

Formula =$MO$
Formula =$M_2O_3$
Hence (b) is the correct answer.