# flipping of coins

## flipping of coins

There is a black table such that u can't see what is inside it..It contains 4 coins placed in at 4-different directions(north, east, south, west).You have to make all the coins facing towards head.

You can do following operations:

1. Flip any one coin.

2. Flip adjacent coins.

3. Flip diagonal coins

4. Flip all coins.

After your every answer table makes a random number of rounds(so u r not sure which coin was flipped previously)

Also after every flip u can ask a question whether all points are facing head...(if all coins are facing head u will get 'yes' as an answer else 'no')

You can do following operations:

1. Flip any one coin.

2. Flip adjacent coins.

3. Flip diagonal coins

4. Flip all coins.

After your every answer table makes a random number of rounds(so u r not sure which coin was flipped previously)

Also after every flip u can ask a question whether all points are facing head...(if all coins are facing head u will get 'yes' as an answer else 'no')

**ankurgutpa**- Posts : 44

Join date : 2008-08-10

Age : 31

Location : Tandon 72

## Re: flipping of coins

phadu haibe beankurgutpa wrote:There is a black table such that u can't see what is inside it..It contains 4 coins placed in at 4-different directions(north, east, south, west).You have to make all the coins facing towards head.

You can do following operations:

1. Flip any one coin.

2. Flip adjacent coins.

3. Flip diagonal coins

4. Flip all coins.

After your every answer table makes a random number of rounds(so u r not sure which coin was flipped previously)

Also after every flip u can ask a question whether all points are facing head...(if all coins are facing head u will get 'yes' as an answer else 'no')

**fault++**- Posts : 1

Join date : 2008-08-11

## HECK !!!!

I Dont think you should expect any answers... unless this ques. starts making any sense...

wat Inside the table..and hw the coins are placed..in different directions...Are their HEADS towards the respective directions or wat ??

==>> Can u Explain a Lil' More..

wat Inside the table..and hw the coins are placed..in different directions...Are their HEADS towards the respective directions or wat ??

==>> Can u Explain a Lil' More..

**Dee2306**- Posts : 7

Join date : 2008-08-12

Age : 30

## Re: flipping of coins

what i interpreted from the question is:

coin are placed like this

...*

* ..... *

...*

now u don't know whether the head or tail on upper side.

now apply any of the four operation to make them all head by considering above constraint

coin are placed like this

...*

* ..... *

...*

now u don't know whether the head or tail on upper side.

now apply any of the four operation to make them all head by considering above constraint

**ankurgutpa**- Posts : 44

Join date : 2008-08-10

Age : 31

Location : Tandon 72

## Re: flipping of coins

neat question buddy.....

just try n give a hint

just try n give a hint

**shivang**- Posts : 22

Join date : 2008-08-11

Age : 30

Location : Tondon 174

## My Solution:

my convention

1) '-' represents check/ask the question

2) each number represents the operation as specified in the question

actual solution:

the sequence of operations is

-4-3-4-2-4-3-4-1-4-3-4-2-4-3-4-

before this sequence ends, u will be able to arrange all the coins in a heads up manner.

if u want check with real coins,i myself tried many times.it seems to work.

explanation:

north,south,etc ... are of not that importance because the table may be spun(to any no of times).

there are basically 6 different arrangements(states) namely

1)4 Heads(final state)

2)4 Tails

3)2 Heads 2 Tails diagonally arranged(meaning same type on diagonally opp).

4)2 Heads 2 Tails adjacently arranged.

5)3 Heads 1 Tail

6)1 Head 3 Tails

the above order is more or less the closeness to the final state that is 1.

i will try and upload a diagram showing the transitions ...it looks similar to the Automata theory state diagrams(not sure if it can be called a transition diagram)

1) '-' represents check/ask the question

2) each number represents the operation as specified in the question

actual solution:

the sequence of operations is

-4-3-4-2-4-3-4-1-4-3-4-2-4-3-4-

before this sequence ends, u will be able to arrange all the coins in a heads up manner.

if u want check with real coins,i myself tried many times.it seems to work.

explanation:

north,south,etc ... are of not that importance because the table may be spun(to any no of times).

there are basically 6 different arrangements(states) namely

1)4 Heads(final state)

2)4 Tails

3)2 Heads 2 Tails diagonally arranged(meaning same type on diagonally opp).

4)2 Heads 2 Tails adjacently arranged.

5)3 Heads 1 Tail

6)1 Head 3 Tails

the above order is more or less the closeness to the final state that is 1.

i will try and upload a diagram showing the transitions ...it looks similar to the Automata theory state diagrams(not sure if it can be called a transition diagram)

**Ramprasadg**- Posts : 12

Join date : 2008-08-13

## series rply

1,0,3,4,27,115,728,5027.......

so terms r lyk 0!+0,1!-1,2!+1,3!-2,4!+3,5!-5.........

so next term ll be 8!+21

so terms r lyk 0!+0,1!-1,2!+1,3!-2,4!+3,5!-5.........

so next term ll be 8!+21

**vivek.nuna**- Posts : 3

Join date : 2008-08-13

## solution:flipping of coins

my solution is also sumwt similar to that posted by ramprasad.....and it definitely does work

**tirth**- Posts : 1

Join date : 2008-08-14

## Re: flipping of coins

you are correct RamP

u hv implemented Automata in the best way

u hv implemented Automata in the best way

**ankurgutpa**- Posts : 44

Join date : 2008-08-10

Age : 31

Location : Tandon 72

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