ALL possible ending points are counted by the multiplication principle of possible directions for each step.
S1,S2,S3,S4,S5,S6
4*4*4*4*4*4 = 4^6 possible strings and hence 4^6 journey ending points.
Sorry, just to clarify. There aren't 4^6 journey end points, there are 4^6 paths, but that is all we need to know for this question...how many paths there are.
If you are interested, I will pose another question along these lines?
@joe-shmosaid Sorry, just to clarify. There aren't 4^6 journey end points, there are 4^6 paths, but that is all we need to know for this question...how many paths there are.
If you are interested, I will pose another question along these lines?
Thanks for the puzzle Jo.
Seems I "overthought" it
I will always look at any puzzle to see if it interests me.
Whether I can solve it or not is another matter but it puts me to sleep at night thinking on it!
@joe-shmosaid 400 is correct for the number of ways to get back to "P" in 6 steps!
ATY is correct about ALL possible paths = 4^6
thus;
P = 400/4^6 = 400/4096 = (20/64)^2 = (5/16)^2
I'll give you both partial credit!
Thank you -good fun!
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04 Mar '21 14:16>1 edit
@vendasaid Thanks for the puzzle Jo.
Seems I "overthought" it
I will always look at any puzzle to see if it interests me.
Whether I can solve it or not is another matter but it puts me to sleep at night thinking on it!
You had 90% of the work done. Not seeing that last 10% was just a normal case of not seeing the forest through the trees! Good Work!
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04 Mar '21 14:21>
Ok...same thing, more steps.
Starting at "P": In exactly 11 steps , how many ways can you get to a location 3 units North and 1 unit East of "P"?
Starting at "P": In exactly 11 steps , how many ways can you get to a location 3 units North and 1 unit East of "P"?
Either I have misread the question,or the answer is none!
You can reach a location 3 steps north and 1 step east of P in 4 steps.
Therefore,you need to take 7 steps to walk from P to P or an equivalent position.
This is the same as the much publicised "bridge" problem of old.
It can't be done!
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04 Mar '21 17:25>1 edit
@vendasaid Either I have misread the question,or the answer is none!
You can reach a location 3 steps north and 1 step east of P in 4 steps.
Therefore,you need to take 7 steps to walk from P to P or an equivalent position.
This is the same as the much publicised "bridge" problem of old.
It can't be done!
Correct! Well done.
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04 Mar '21 17:34>1 edit
Ok...Next. Probably a bit more challenging.
Given exactly "k" steps in any cardinal direction from "P", how many positions can be reached?
Afraid not. If you haven't yet; start with k = 1 step and work your way up. The pattern should jump out at you within the first few "k". Proving it in general for all "k" isn't quite so simple.
I've tried all that,with little dots on a piece of paper.
First, I went up to 7 "dots" in a straight line east and put a dot at north and south at every step.
I then added up the dots and came up with the answer 3k+1(1 representing an 8th step east)
I then tried with random directions (e.g 2 steps east 1 step north etc) but could only count 3k this way.
I suspect I need a different approach or a bigger piece of paper!!