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Old 2005 April 25th, 02:11 AM   #25 (permalink)
lego2401
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Re: A complete guide to Permutation, Combination and Probability. All you need for GM

Quote:
Originally Posted by TwinnSplitter
personally I just take the adhoc approach, as I haven't really come to have a fixed, step by step strategy. I just look at the problem, try and understand what it's asking, and execute accordingly.

As for the question you posted, I would divide them up into two groups: blue and not blue (not blue being red and green). The first time you pick, the probability of getting "not blue" is 4/7, and the second time you pick, the probability of getting "not blue" (assuming you got "not blue" the first time) is 3/6. The third time has probability 2/5. Thus, the probability of getting no blues is:

(4/7) x (3/6) x (2/5) = 4/35


I do agree with you that these questions are on the level of what you'll see on the GMAT, and I think that a lot of people are spending way too much time on extremely difficult probability and not enough time on the more fundamental aspects of GMAT math.

I hope you meant there that you agree with me that these questions are NOT on the level of what'll be seen on the GMAT I have being saying that for a while, prob will be atmost a couple of question, and theyll be easy ones. I think people have to focus on other points and spend less time on this topic .........
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