Secondary Train Puzzle involving cats

L D[AR2P#0.0]

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Following on from Daba's train puzzle, here's another and it really does involve cats!


Code:
A train travelling at contant speed approaches a tunnel.
At the entrance and exit of the tunnel
are two trained measuring cats that walk at exactly
the same speed in 1 metre steps.
When the train reaches the tunnel entrance
the first cat walks in the opposite direction
to the train travel and stops when it reaches
the end of the train. 
When the front of the train comes out of the tunnel,
the other cat walks
in the same direction as the train and keeps walking until
the rear of the train passes it.

Each cat walks an integer number of steps 
and the total number of steps in their measurement is less than 11.
The cats pass on the puzzle details and total number of steps
to a passing dog and ask him to determine the length of the train.

 
The dog says "I can't tell you the length of the train, I need more information"

The cats tell the dog that the train is shorter than the total
length they have walked.
 
The dog says "Thank you, I can now determine the length of the train".

How long is the train in metres?
Answers via PM
 
Last edited:
Actually, I must admit that logically it is implied that is the front of the train that reaches the tunnel exit. Otherwise, the 2nd cat would stop walking at the same time that it starts to walk.
But it is easier for me to visualize now :)

And the cats are safe, the train cant hit them, I assume.
 
Hmmmm...

Is it really solvable ?
If the train moves really fast and less than 2 meters long, so that it passes each cat in a second or less, then the cats will both only move 1 step and the conditions of less than 11 steps in total and length is less than the total number of steps will both be met, no matter the exact length of the train as long as it is less than 2 meters.
 
Hmmmm...

Is it really solvable ?
If the train moves really fast and less than 2 meters long, so that it passes each cat in a second or less, then the cats will both only move 1 step and the conditions of less than 11 steps in total and length is less than the total number of steps will both be met, no matter the exact length of the train as long as it is less than 2 meters.

I think it's a toy train :confused:
 
Following on from Daba's train puzzle, here's another and it really does involve cats!


Code:
A train travelling at contant speed approaches a tunnel.
At the entrance and exit of the tunnel
are two trained measuring cats that walk at exactly
the same speed in 1 metre steps.
When the train reaches the tunnel entrance
the first cat walks in the opposite direction
to the train travel and stops when it reaches
the end of the train. 
When the front of the train comes out of the tunnel,
the other cat walks
in the same direction as the train and keeps walking until
the rear of the train passes it.

Each cat walks an integer number of steps 
and the total number of steps in their measurement is less than 11.
The cats pass on the puzzle details and total number of steps
to a passing dog and ask him to determine the length of the train.

 
The dog says "I can't tell you the length of the train, I need more information"

The cats tell the dog that the train is shorter than the total
length they have walked.
 
The dog says "Thank you, I can now determine the length of the train".

How long is the train in metres?
Answers via PM

What about the other two cats? :ROFLMAO:
>> At the entrance and exit of the tunnel
>> are two trained measuring cats

two cats at each tunnel opening? or two cats total?
Programmers have to know!

:p
 
What about the other two cats? :ROFLMAO:
>> At the entrance and exit of the tunnel
>> are two trained measuring cats

two cats at each tunnel opening? or two cats total?
Programmers have to know!

:p




Before this was posted, LD asked me to look at this, and he spent a lot of effort tweaking it from my comments and attempts at removing ambiguities. It's actually pretty clever.



I saw this one but didn't say anything, so this is my bad.


So haha on me.
 
Before this was posted, LD asked me to look at this, and he spent a lot of effort tweaking it from my comments and attempts at removing ambiguities. It's actually pretty clever.



I saw this one but didn't say anything, so this is my bad.


So haha on me.

I was just picking at the proverbial ball of yarn, so to speak. All in good fun!
Who is driving the train, Feathers McGraw?
 
Last edited:
I think this is inferred but just checking.
I assume a step ends at exactly the same time as the back of the train passes the cats (exact integer number of steps).

Keith
 

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