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How many paths are there from A to B, if every step must be up or to the right?

 

Thanks in advance!

 Feb 5, 2019
 #1
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Darn, waiting for moderation. Well, it is a 4 by 5 grid with an A in the bottom left hand side, and a B in the top right hand side.

 Feb 5, 2019
 #2
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YAY! Not anymore!

Guest Feb 5, 2019
 #3
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We have the following set of moves

 

(right, right, right, right, right, up, up, up ,up)

 

So.....we have 9 possible moves  and we want all the ordered sets where any  4 of them are  "up" or any 5 of them are "right"

 

So....the total pathways are  = C(9,4) = C(9,5)   = 126 paths

 

 

cool cool cool

 Feb 5, 2019
edited by CPhill  Feb 5, 2019
edited by CPhill  Feb 5, 2019
 #4
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Thanks! You were right!

Guest Feb 5, 2019

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