Well, you are a clever girl, so i'm sure you can do this...
Here is the formula,
Number of moles= given volume / molar volume ( that is 24 cubic decimeter or 24000cubic centimeter)
If you the given volume is in cubic decimeter, then make sure that the molar volume is also in cubic decimeter. And the same rule applies if it's in cubic centimeter.
Hope you know it now
