How to solve it
- Thread starter lldk
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how may routes?
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The point X is not on a NS grid. Does the path have to follow grid-lines? As posted, the answer should be "NO" - because the problem states "The only condition imposed...."
yes,have to follow the grid line, but ca only go east or north
pka
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Concentrate on the lower left grid crossing nearest to \(X\). Starting at A, using the rules, if a path is to pass through \(X\) we must use that grid point.
To get there we must move two blocks north & three east. That can be done in \(\dfrac{5!}{2!\cdot 3!}=10\) ways. That is the number of ways to rearrange the string \(NNEEE\). Then move through \(X\), one block, and then on to \(B\) moving four blocks north & four east.
To get there we must move two blocks north & three east. That can be done in \(\dfrac{5!}{2!\cdot 3!}=10\) ways. That is the number of ways to rearrange the string \(NNEEE\). Then move through \(X\), one block, and then on to \(B\) moving four blocks north & four east.
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pka
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If you would post your solution then it will help others.
pka
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Yes, that gives the answer but nothing else. How does that help?