IF ALL NITROGEN ATOMS FROM .1 MOLE nO2 AND .2 MOLE N2O4 ARE REMOVED THEN HOW2 MANY MOLES OF N2 CAN BE PREPARED FROM IT?

Answer 1

Please don't post in all caps. It makes the question difficult to read.
0.1 mol NO2 and 0.2 mol N2O4.

So you have 0.1 mol N from NO2 = 0.05 mol N2 from NO2.
You have 2*0.2 = 0.4 mol N2 from N2O4.
Total is 0.4 + 0.05 = ?