Just to chime in and reiterate what others have said, it depends on the context of your situation. If you are already scoring relatively well i.e. 128 or greater then one month is probably not enough because those last few points require a tremendous amount of effort. On the other hand if you are scoring 50% or lower than yeah definitely enough time to develop some test taking strategy to boost it up. It really depends though, as others have stated until you are comfortable and have mastered an approach to answering CARS questions stop doing so many passages. Unless you have a unlimited supply of passages you are just burning through precious material without any sense of direction. Remember that NS tends to be a little more on the difficult side.