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Finding number of path Help!!

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Finding number of path Help!!

by anuu » Sun Jun 26, 2011 3:20 pm
Hi,

I came across the below problem in an online test. I got the wrong answer.
Any suggestion on the logic pls?

A person starts from A and passes through B and C,arrives D at last. If he go forward only to east and north, in how many way can he finish the trip?

a.20
b.32
c.36
d.56

Answer is c

My aprroach is: I came up with a grid comprising total of 6 moves(3 R's and 3Us) from A to D.

Hence total number of moves is 6c3 = 20 moves.

Can anybody pls explain the problem with the correct concept?

Regards,
Anu
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by Frankenstein » Mon Jun 27, 2011 9:28 pm
Hi,
There must some figure attached to this question. Otherwise, it is impossible to answer this question. Please attach the grid.
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by casperkamal » Tue Jun 28, 2011 3:02 am
Hi Anuu,

refer here...

https://www.beatthegmat.com/how-to-solve ... 86056.html
Kamal
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by arnabis2good » Tue Jun 28, 2011 6:22 pm
Can we not answer without the grid? There are 6 possible moves :

N-fwd, E-fwd, W-fwd, W-bckwd, S-fwd, S-bckwd

If there are 4 points in this trip, we have to select any 3. So the answer should be 6P3.

Do you see any issue with this approach?
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by Frankenstein » Tue Jun 28, 2011 8:40 pm
arnabis2good wrote:Can we not answer without the grid? There are 6 possible moves :

N-fwd, E-fwd, W-fwd, W-bckwd, S-fwd, S-bckwd

If there are 4 points in this trip, we have to select any 3. So the answer should be 6P3.

Do you see any issue with this approach?
Hi,
This doesn't make sense at all to me. Without knowing the grid, there is no way one can solve as we do not know how many ways are there between two adjacent points. Moreover, you cannot justify your answer as well because your answer is not in options. So, that is at least some indication.
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