Great question!
First, many roman numeral problems take longer to solve than "regular" problems—so the first thing to ask yourself is whether you even want to spend time on this problem. If it's a topic that is harder for you and/or the problem looks really complicated, the best call might be to guess and move on.
Next, the mix of answer choices changes, so there isn't a way to set up a standard "elimination grid," like you do for DS. But there are still some best practices as you work through the problem:
— Start with whichever statement seems easiest to you (ie, don't necessarily do them in order). If they all seem about the same, either start with the first one or start with one that appears in about half of the answers (so that you can cross off multiple answers regardless of whether this statement does or doesn't work).
— As soon as you've processed one of the three statements, cross off all of the answers that can be crossed off.
— Then, before you choose which statement to work on next, examine the remaining answer choices. You may discover, for example, that all of the remaining answers include statement II...so it must work (or that none of them include statement II, so it must not work). Either way, you don't have to bother to check statement II.
— If more than one statement still remains, again choose whichever one looks easiest to you.
— If you can tell that you're going over 2 minutes and there's still a lot of work to do, consider just guessing from among the answers remaining. You've narrowed down your answers somewhat, so you're still in a good position on the problem. Spending a lot more time might not be worth it.
By the way, I would *not* start with the one that shows up most frequently first—the Internet hasn't thought that logic through. For example, let's say one statement appears in 4 answers. If it works, then you'll only be able to cross off one answer...and if it does appear in 4 of the answers, then chances are it does work.
Go for easiest first—or, if they're all about the same, choose one that appears in either 2 or 3 answers. That way, you know you'll be able to eliminate either 2 or 3 answers after you've evaluated it.
