Problem Solving Skills for Mathcounts Competitions
Book Store => Bookstore => Twenty Files Questions => Topic started by: Jane Chen on October 06, 2010, 09:21:01 AM
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Proof the formula "how many ways to walk"
Here is a simple proof:
Walking from (0, 0) to (5, 4), one way is as shown in the picture.
It is the same solution as to the question: how many ways are there to arrange
b a b b a a b a b
in a row?
Similarly we can get the ways to walk from (0, 0) to (m, n).