' I suggest you read about how to make a question on stack exchange, as yours seems to lack essential things like research effort, details on how did you try to approach your problem, amongst other things. Not many people will really take their time to answer you, if you don't show you did some effort yourself.
As to the question. Just a small search and you would find that Avogadro's law relates the volume of a gas with the number of molecules. It states that if you have two different gases in the same pressure and temperature, the number of molecules will be the same. So knowing 1 mol…