I am going through the section of Per. and com. (combinatorics) from Manhattan's 5th edition.
The concept is properly explained, however, when I look at other resources on the internet they are full of formulaes with nCr etc etc.
(This include the problem set and the solution on the GMAT club also)
Personally, I like the Manttn approach, but I am worried in case the GMAT frames the question with nCr's and nPr's?
Am I missing something by sticking to only the Manttn? (It doesn't cover the problem with people sitting in the circle.....etc..)
Let me know...I am lost I think.