Equal volumes of nitrogen and carbon monoxide at the same temperature and pressure have the same?

I just want to add a little more info about answer choice 1. Since it is given that the two gases have equal volume, it just remains to determine if they have the same molecular weight. Whether they do or not for this question depends on how many significant digits you are using. If you are just using 4, then both have weights of 28.01. If you calculate it more precisely, though, CO=28.0101 while N2 =28.0134. You may need more information to determine if you should think of 1 as true. In the strictest sense, 1 would be incorrect, but they may be close enough for the purposes of the question.