Hey smar83,
I'll let the community help you out with book recommendations (I'm pretty partial to the Veritas Prep series, but that's a fairly biased opinion). I did want to offer a quick word of advice regarding Work/Rate problems, though, since I saw this title.
Don't worry about memorizing a formula - just remember "miles per hour", which you'll almost certainly see in some fashion every day between now and when you take the test.
Miles ---> Distance
Per ---> Divided by
Hour ----> Time
So Rate = Distance/Time, and you can replace "Distance" with whatever you want to accomplish (producing widgets-per-hour or whatever).
At that point, every time you're given a rate, you're given an equation, so you can use the algebra to go from there. And if they give you more variables than equations, try to find relationships between variables, such as:
-If two cars meet, they must do so at the same time, so T(a) should equal T(b), unless one left earlier or later in which case you add/subtract time as needed.
-If two trains meet, then they've each covered part of the total distance, so the distance of train A = Total Distance - Distance of Train B.
With practice you can definitely become pretty adept at these, but hopefully that strategy helps, too. Every rate is an equation, and you know the 'formula' without having to think about it!
Brian Galvin
GMAT Instructor
Chief Academic Officer
Veritas Prep
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