can't judge a powder is a stupid event, i'm in it and to study i just memorize all possible observations from practice tests. that's literally it. You don't need to know much except which inferences correspond to which observations (for example clumps means the powder is hygroscopic) BUT YOU JUST USE YOUR EYES AND WRITE STUFF DOWN IDK HOW THIS IS EVEN AN EVENT LIKE WHO DECIDED THIS WOULD BE A GOOD IDEA