when metal burnt its weight is increased by 13%.the equivalent of metal is

Equivalent weight of O2-(oxide) ion is : Molar mass of oxygen/charge on oxygen
​ = 16 g mol-1/2 mol eq-1
= 8 g eq-1
Oneequivalent of the metal reacts with one equivalent of oxygen to form metal oxide.
Let Mbe the equivalent weight of the metal.
Therefore Mgrams of the metal will react with 8g of oxygen. The corresponding metal oxide will have mass 8 gram more than mass of metal M. This 8 gram is 13% of M.
Or we can say that M x 13/100 = 8 gram
So, M = 100 x 8/13 = 61.54 g