Book for permutations and combinations

<p>Permutations and combinations is my weakness area and would like to improve.
Can you guys suggest resource/s you have been using which has practice problems?</p>

<p>there’s really not much to it. But the new math sat plan by philip keller explains it pretty well and he’s great for math in general</p>

<p>use bruladi’s combinatorics.</p>

<p>There are whole books on combinatorics/permutations. For example, David Patrick’s “Introduction to Counting and Probability,” (on AoPS) which is mostly used for MATHCOUNTS and AMC10, but can easily be applied to SAT problems. I’m sure there are other books out there, too.</p>

<p>mathcounts, amc and olympiad books are a waste of time.
Learn the method of counting and its application in probability.</p>

<p>MATHCOUNTS and AMC books generally teach counting and probability pretty well. I used these books when I prepared for MATHCOUNTS and AMC competitions, did pretty well in them, and scored 800 on SAT math without any additional SAT preparation.</p>

<p>Be cautious though, some AMC (and even MATHCOUNTS) questions can be quite tricky, even harder than the hardest of the SAT problems.</p>