The equivalent weight of a metal is double than that of oxygen.How many times is the weight of its oxide greater than the weight of metal ?

The first sentence doesn't make much sense... the equivalent weight, implies that the metal has the same weight as oxygen and then it says that it's double?

Or do you mean the same amount of moles of metal weight twice that of that amount of oxygen?

If that's so, then you know that the weight of the metal is twice 16, which is 32.

Now, find what metal that is by looking in your periodic table, find what oxide is produces and find the weight of that oxide.

Lastly, find the ratio.