Use of charts and tables in PS

[wayneyau1214]

I recently bought a copy of the manhattan complete strategy guide set which includes their own explanations to the OG problems on their website. I noticed that for a lot of the PS problems, they tell you to make charts and tables to organize info before you start doing the math, whereas the explanations in OG tend to tell you to come up with an algebraic equation to solve for a variable. I'm a little skeptic about tables and charts...they seem to be a good way to organize information IF you have the time. The problem is, there is hardly enough time on the test to actually come up with a table AND fill out the numbers. Did anyone else have the same problem? Should I ignore the charts and tables method if I'm not comfortable with it?

[Jim@StratusPrep]

I personally do not use them on anything except DS questions.

[wayneyau1214]

What about the "hard" questions? Do find it necessary to rearrange the data for it to make sense?

[Ian Stewart]

Organization tends to save time, especially in complicated questions. If you have, say, an average speed problem, you have 9 numbers to keep track of (the distance, time and speed for each of the two parts of the trip, along with the total distance, time, and average speed for the two parts combined). If you write those numbers chaotically on your page, you can lose a lot of time trying to find the number you need to carry out the next step in the solution. If instead the numbers are neatly arranged in a table, you never waste any time trying to find the next number you need to use. You need to write the numbers down no matter what you do, so it's vastly better to write them down in some organized way.

Now, I don't like tables much, and I tend only to use them for average speed problems. But in, say, overlapping sets problems, I'll almost always draw a Venn diagram, and in a mixtures or weighted average problem, I'll very often draw the averages on a number line. It can be especially helpful on GMAT DS questions to have ways to usefully visualize information, since you can often then 'see' just what information is there and what's missing. That's a lot harder to do if you're staring at a lot of letters in an equation.

Of course, on easier questions it won't matter much what you do, but on harder questions, I find these kinds of methods indispensable.