Question: Distributing Coins

Comment on Distributing Coins

why isn't here "multiply"? can you explain it please?
greenlight-admin's picture

In this lesson, we're looking at the technique of Listing & Counting, in which we simply list all possible outcomes and them count those outcomes.

So, there aren't any sophisticated counting techniques involved here (like using the Fundamental Counting Principle, which involves multiplication)

can you please explain how can we solve same question, using fundamental counting principle?

greenlight-admin's picture

There's no way to solve this question using the fundamental counting principle, unless we consider a crazy number of cases. The purpose of the question is to show the utility of listing and counting.

I have one more question,

how many 3 digit number can be formed so that addition of 3 digit will yield 6. choose any digit out of 0,1,2,3,4,5,6.

please help me in understanding this.
greenlight-admin's picture

That question requires us to use a technique known as partitioning, which is beyond the scope of the GRE.

If you're interested in learning more, see my response to the the following question: http://www.beatthegmat.com/very-tricky-counting-problem-t25349.html

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