Latest SELF Aptitude Question SOLUTION: Alice and Bob play the following coins-on-a-stack game. 20 coins are stacked one above the other.One of them is a special (gold) coin and the rest are ordinary coins. The goal is to bring the gold coin tothe top by repeatedly moving the topmost coin to another position in the stack.Alice starts and the players take turns. A turn consists of moving the coin on the top to a position i belowthe top coin (0 = i = 20). We will call this an i-move (thus a 0-move implies doing nothing). The provisois that an i-move cannot be repeated; for example once a player makes a 2-move, on subsequent turnsneither player can make a 2-move. If the gold coin happens to be on top when it's a player's turn thenthe player wins the game. Initially, the gold coinis the third coin from the top. Then find the valid game between alice and bob. a) In order to win, Alice's first move should be a 1-move. b) In order to win, Alice's first move should be a 0-move. c) In order to win, Alice's first move can be a 0-move or a 1-move. d) Alice has no winning strategy.

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(#M40002601) SELF aptitude question Keep an EYE

Alice and Bob play the following coins-on-a-stack game. 20 coins are stacked one above the other.One of them is a special (gold) coin and the rest are ordinary coins. The goal is to bring the gold coin tothe top by repeatedly moving the topmost coin to another position in the stack.Alice starts and the players take turns. A turn consists of moving the coin on the top to a position i belowthe top coin (0 = i = 20). We will call this an i-move (thus a 0-move implies doing nothing). The provisois that an i-move cannot be repeated; for example once a player makes a 2-move, on subsequent turnsneither player can make a 2-move. If the gold coin happens to be on top when it's a player's turn thenthe player wins the game. Initially, the gold coinis the third coin from the top. Then find the valid game between alice and bob.
a) In order to win, Alice's first move should be a 1-move.
b) In order to win, Alice's first move should be a 0-move.
c) In order to win, Alice's first move can be a 0-move or a 1-move.
d) Alice has no winning strategy.

Solution

(b)In order to win, Alice's first move should be a 1-move....
reason:there are two possibility after 1- move by Alice:-
1. when bob takes 0-move....then the coin config is same ..... but now alice can neither take 1-move nor 0-move.... so she has to take 2 or greater move(let it be 2 move)............
now we have only one coin above the gold coin......now bob can neither take 1-move nor 0-move nor 2-move.... so she has to take 3 or greater move.......
but the move greater then 2-move brings gold coin on top....makes alice win...

2.now bob takes 2-move after alice's first move....... now thre is only one coin above the gold coin..... so Alice takes 0-move........now we have only one coin above the gold coin......now bob can neither take 1-move nor 0-move nor 2-move.... so she has to take 3 or greater move.......
but the move greater then 2-move brings gold coin on top....makes alice win...

This answer is given by ROHIT KUMAR and is the correct answer

Like manish sir answer on facbook.

Submited By-- aniruddha mandal (1 year ago)

Puzzle Status: Solved

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yasaswini  (1 year ago)

Its just a simple logic which am giving. But its not the right procedure.. Bt it will work for this type of questions..
The answer is C

Check the condition in the last line of the question. If they had given that ",initially the gold coins the THIRD coin from the top" consider the position like first,third,fifth positions then answer will be third. If it is in even position then answer will be option 'd'.

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Nandita Pandey  (1 year ago)

Alice's 1st move should b a 0 move

Is this solution Helpfull? Yes (1) | No (10)  

(#M40000446) TCS MATHS PUZZLE Stacked Gold Coin Keep an EYE

Alice and Bob play the following coins-on-a-stack game. 20 coins are stacked one above the other. One of them is a special (gold) coin and the rest are ordinary coins. The goal is to bring the gold coin to the top by repeatedly moving the topmost coin to another position in the stack.


Alice starts and the players take turns. A turn consists of moving the coin on the top to a position i below the top coin (0 = i = 20). We will call this an i-move (thus a 0-move implies doing nothing). The proviso is that an i-move cannot be repeated; for example once a player makes a 2-move, on subsequent turns neither player can make a 2-move.


If the gold coin happens to be on top when it's a player's turn then the player wins the game.


Initially, the gold coinis the third coin from the top. Then
Alice has no winning strategy.
In order to win, Alice's first move should be a 1-move.
In order to win, Alice's first move can be a 0-move or a 1-move.
In order to win, Alice's first move should be a 0-move.

Asked In TCS Submited By-- Sathish (2 year ago)

Puzzle Status: Solved     By »» raviteja

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raviteja  (2 year ago)

in order to alice first move should be 1-move

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kuhel chowdhury  (2 year ago)

BAL CHAL GULO AKTAO O THIK KORE ANSWER DITE PARE NA

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avishek chakraborty  (1 year ago)

d) Alice has no winning strategy
Case 1:suppose Alice starts with a 0 move. Now bob cleverly goes for a 2 move so that there is only one coin above the gold coin. Now irrespective of alice's move, Bob wins.
Case 2:suppose alice stats with a 1 move it barely makes any difference. Again Bob goes for a 2 move and he wins. So alice has no winning strategy at all.

Is this solution Helpfull? Yes (17) | No (17)  

neha   (2 year ago)

Alice has no winning strategy.

Is this solution Helpfull? Yes (7) | No (30)  

Menakshi  (2 year ago)

please explain clearly

Is this solution Helpfull? Yes (4) | No (3)  

arun  (2 year ago)

plz give explanation

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Bhavani  (2 year ago)

Plz explain your answer

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SRIJITA  (2 year ago)

plz gv explaination

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Karan Parmar  (1 year ago)

In order to win Alice’s first move should be a 1 move

Is this solution Helpfull? Yes (1) | No (1)  

shilpa verma  (9 Month ago)

plzz give expalnation..

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(#M40000909) TCS MATHS PUZZLE Tcs recent paper Keep an EYE

Alice and Bob play the following coins-on-a-stack game. 50 coins are stacked one above the other. One of them is a special (gold) coin and the rest are ordinary coins. The goal is to bring the gold coin to the top by repeatedly moving the topmost coin to another position in the stack.Alice starts and the players take turns. A turn consists of moving the coin on the top to a position i below the top coin (0 ≤ i ≤ 20). We will call this an i-move (thus a 0-move implies doing nothing). The proviso is that an i-move cannot be repeated; for example once a player makes a 2-move, on subsequent turns neither player can make a 2-move. If the gold coin happens to be on top when it's a player's turn then the player wins the game. Initially, the gold coinis the third coin from the top. Then
a) In order to win, Alice’s first move should be a 0-move.
b) In order to win, Alice’s first move should be a 1-move.
c) Alice has no winning strategy.
d) In order to win, Alice’s first move can be a 0-move or a 1-move

please explain it me,its urgent..

Asked In TCS Submited By-- Rupkatha Nag (2 year ago)

Puzzle Status: Solved     By »» suchandra raavi

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suchandra raavi  (2 year ago)

First see the fig at 6th Q in the link:
http://writer.zoho.com/public/suchandra/ques
1)If Alice selects 0-move as first move, Bob will do 2-move. Now the position will be like on the 4th fig. Now Alice has to perform atleast 1-move. Then she looses. 2)Now Alice selects 1-move as her first move. Then if Bob selects 0-move, Alice selects 2-move and wins. If Bob goes for 2-move,Alice selects 0-move and wins. So in either case Alice wins. So b is the ans.

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Krishna KAnt Tiwari  (2 year ago)

agreed wid suchandraa............

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TANU MUKHERJEE  (1 year ago)

ans will be 0move or 1 move of alice

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(#M40000987) TCS MATHS PUZZLE Gaar Fatano Question..Please Explain Keep an EYE

Alice and Bob play the following coins-on-a-stack game. 20 coins are stacked one above the other. One of them is a special (gold) coin and the rest are ordinary coins. The goal is to bring the gold coin to the top by repeatedly moving the topmost coin to another position in the stack.


Alice starts and the players take turns. A turn consists of moving the coin on the top to a position i below the top coin (0 = i = 20). We will call this an i-move (thus a 0-move implies doing nothing). The proviso is that an i-move cannot be repeated; for example once a player makes a 2-move, on subsequent turns neither player can make a 2-move.


If the gold coin happens to be on top when it's a player's turn then the player wins the game.


Initially, the gold coinis the third coin from the top. Then
Alice has no winning strategy.
In order to win, Alice's first move should be a 1-move.
In order to win, Alice's first move can be a 0-move or a 1-move.
In order to win, Alice's first move should be a 0-move....
Please Explain Your Answer..

Asked In TCS Submited By-- abhishek (2 year ago)

Puzzle Status: Solved     By »» Sofikul Mallick

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Sofikul Mallick  (1 year ago)

In order to win alice's first move should be a 1-move
BECAUSE:
if alice's first move is 1.the there are 2 coins above the gold coin.The there are two chances that Bob may choose 0 move or 2 move.
i>If he choose 0 move then there are 2 coins above the gold one.
Then bob's choice is 2 move. then there are 1 coin above gold and Bob's move must be 3 or greater. So, when alice turns come then the gold is above.So alice win the game.
ii> Similarly, if bob' choice is 2 then also Alice win the the game.

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Rohit kumar  (1 year ago)

(b)In order to win, Alice's first move should be a 1-move....
reason:there are two possibility after 1- move by Alice:-
1. when bob takes 0-move....then the coin config is same ..... but now alice can neither take 1-move nor 0-move.... so she has to take 2 or greater move(let it be 2 move)............
now we have only one coin above the gold coin......now bob can neither take 1-move nor 0-move nor 2-move.... so she has to take 3 or greater move.......
but the move greater then 2-move brings gold coin on top....makes alice win...

2.now bob takes 2-move after alice's first move....... now thre is only one coin above the gold coin..... so Alice takes 0-move........now we have only one coin above the gold coin......now bob can neither take 1-move nor 0-move nor 2-move.... so she has to take 3 or greater move.......
but the move greater then 2-move brings gold coin on top....makes alice win...

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Somil Nain  (2 year ago)

first move must be 1 move
Already solved repeated question

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Sambit Dutta  (2 year ago)

In order to win, Alice's first move should be a 1-move

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kapil   (2 year ago)

no winning strategy

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saurabh kolhe  (2 year ago)

for this question there is no trick or any explanation.
just mug up the answer is that option in which Alice will make first move as 1 or any option having first 1 move.

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saurabh himanshu  (1 year ago)

in order to win aliace first move should be 0.

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saurabh himanshu  (1 year ago)

In order to win, Alice's first move should be a 0-move.
Since It is Way to Win 0-move by Alice 1-move by Bob 2-move by Alice Make Third Coin top
The Answer is Alice First move should be 0-move

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Pooja Desai  (1 year ago)

the answer should be in order to win alice's first move can be a 0-move or a 1-move

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Vivek Gupta  (1 year ago)

Alice has no winning strategy

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Mirdul Mor  (1 year ago)

In order to win Alice first move should be 0-move

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akash   (1 year ago)

alice move must be 1 move

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N.NITHYA  (1 year ago)

for this question the answer is alice has no winning stratergy

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Uday Pratap Singh  (1 year ago)

Alice has no winning strategy.

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gaurav pathak  (1 year ago)

!! answer would be first one....................
to win alice.alice,s first move should b one-move
coz
in case of first 0 move,opposote one can,nt be move 0 den he wil move one...........den next time alice will move first d,got golden coin on upper surface.....
if alice move z 1 den opposite can,t be move 1 den he will 0.....den alise has to move o and opposite wil move 1 ,den he wil get coin....

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(#M40001605) TCS MATHS PUZZLE latest question Keep an EYE

Alice and Bob play the following coins-on-a-stack game. 50 coins are stacked one above the other. One of them is a special (gold) coin and the rest are ordinary coins. The goal is to bring the gold coin to the top by repeatedly moving the topmost coin to another position in the stack.Alice starts and the players take turns. A turn consists of moving the coin on the top to a position i below the top coin (0 ≤ i ≤ 20). We will call this an i-move (thus a 0-move implies doing nothing). The proviso is that an i-move cannot be repeated; for example once a player makes a 2-move, on subsequent turns neither player can make a 2-move. If the gold coin happens to be on top when it's a player's turn then the player wins the game. Initially, the gold coinis the third coin from the top. Then
a) In order to win, Alice’s first move should be a 0-move.
b) In order to win, Alice’s first move should be a 1-move.
c) Alice has no winning strategy.

d) In order to win, Alice’s first move can be a 0-move or a 1-move

Solution

(b)In order to win, Alice's first move should be a 1-move....
reason:there are two possibility after 1- move by Alice:-
1. when bob takes 0-move....then the coin config is same ..... but now alice can neither take 1-move nor 0-move.... so she has to take 2 or greater move(let it be 2 move)............
now we have only one coin above the gold coin......now bob can neither take 1-move nor 0-move nor 2-move.... so she has to take 3 or greater move.......
but the move greater then 2-move brings gold coin on top....makes alice win...

2.now bob takes 2-move after alice's first move....... now thre is only one coin above the gold coin..... so Alice takes 0-move........now we have only one coin above the gold coin......now bob can neither take 1-move nor 0-move nor 2-move.... so she has to take 3 or greater move.......
but the move greater then 2-move brings gold coin on top....makes alice win...
This answer is given by ROHIT KUMAR and is the correct answer

Like manish sir answer on facbook.

Asked In tcs Submited By-- Aditi Sharma (1 year ago)

Puzzle Status: Solved

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(#M40002350) TCS MATHS PUZZLE Keep an EYE

Alice and Bob play the following coins-on-a-stack game. 100 coins are stacked one above the other. One of them is a special (gold) coin and the rest are ordinary coins. The goal is to bring the gold coin to the top of the repeatedly moving the topmost coin to another position in the stack. Alice starts and the players take turns. A turn consists of moving the coin on the top to a position I below the top coin (for some I between 0 and 100). We will call this as i-move (thus a 0-move implies doing nothing). The proviso is that an i-move cannot be repeated, for example once a player makes a 2-move, on subsequent turns neither player can make a 2-move. If the gol coin happen to be on the top when it’s a player’s turn then the player wins the game. Initially, the gold coin is the third coin from the top. Then

In order to win, Alice’s first move should be a 1-move.
Alice has no winning strategy.
In order to win, Alice’s first move can be a 0-moveor a 1-move.
In order to win, Alice’s first move should be a 0-move.

Asked In TCS Submited By-- partha (1 year ago)

Puzzle Status: Solved     By »» Debadrita Datta

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Debadrita Datta  (1 year ago)

if alice makes a 0 move, then Bob will definitely make a 2 move which will leave only one coin on top of the gold coin and alice will have to make a non zero move as she has taken 0 already thus bringing the gold coin on top and making bob win. So in order to win, Alice CANT make a zero move.

now if alice makes a one move, then it will leave the stack in its initial position only.... now if bob makes a zero move, it would make alice win(as explained earlier) and if he makes a 2 move it will leave just one coin above the gold, then alice will definitely take a zero move leaving bob no other choice but to take a non zero move which would bring the gold coin on top and make alice win...
so to win, alice must make a ONE move...

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Subhas Das  (1 year ago)

Alice has no winning strategy,
coz,if Alice make 0 move then Bob has to make either 1 or 2 move,then Bob has the chance to win.(as the gold coin is at the third position from top.)
If Alice make 1 move,Bob has to make either 0 or 2 move,in that case,Alice will never win.

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thejwal pavithran   (1 year ago)

sorry for last answer.its wrong.
alice has to make a 1-move to win

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thejwal pavithran   (1 year ago)

if alice does a 0 move,bob would do 2 move ensuring a win.
so alice cannot start with a o-move.

if alice does a 1 move,bob would do a 2move ensuring a win
so alice cannot start with a 1-move.

so no winning strategy.

Is this solution Helpfull? Yes (4) | No (7)