Data Sufficiency - Rephrasing the Stem

[manochsa]

Hey guys,

A question on strategy. How often should I be rephrasing data sufficiency question stems, and how what do I need to consider in making the decision to rephrase/rework, especially algebraic stems?

I typically try to rephrase d/s algebraic stems by factoring out, using FOIL distribution, isolating variables, etc. Oftentimes I find it was a wasted effort -- that the problem is more easily addressed with the original stem.

Is there something I should be looking for here in deciding whether to rephrase the stem, for example, maybe statements I and II are simple equalities, such as x = 3, or r>0.

Any suggestions?

Thanks,

Sanjay

[manochsa]

Another thought on the need to rephrase -- is there something in the statements that would indicate I should be thinking NPZ, FIZ, and so try to rephrase the stem accordingly. If so, what are the indicators of an NPZ or FIZ problem?

Thanks again,

Sanjay

[Ben Ku]

NPZ and FIZ are typically strategies to help you pick numbers, not rephrase.

Rephrasing is a tool to help you simplify a DS question stem. Obviously a question such as "is x > 0?" does not need rephrasing. However, a question such as "What is 2x / 3y?" can be rephrased (or simplified) to "What is x / y?"

Sometimes rephrasing is obvious. For example, if the question stem includes "If 2(x - y) + 3(x + y) = 18, ..." then it's pretty obvious that you should distribute and combine the x and y terms.

Sometimes rephrasing just requires practice. The example I first give "What is 2x / 3y?" is like this. If you do it a bunch of times, you'll start seeing how to simplify it.

Sometimes rephrasing is very complex. If there is not an obvious rephrase, don't waste a lot of time trying to figure it out. If you can't see it in about 15 seconds, I suggest finding a pattern to figure out what you're looking for.

The strategy guides includes rephrases of many OG problems; practice with these OG problems and see if you can come up with similar rephrasings.