Question

In: Economics

Suppose two players take turns playing another version of the parlor game discussed in class on...

Suppose two players take turns playing another version of the parlor game discussed in class on Tuesday. In this version, players can say any whole number between 1 and 10. The first person to get the running total to 25 wins. Do you want to go first or second? Figure out the optimal strategy for this game. Show your work.

(b) (5 points) ECN-322 only for this part: Suppose two players take turns playing another version of the parlor game discussed in class on Tuesday. In this version, Player 1 can say any whole number from 1 to 5. Player 2 can say any whole number from 1 to 6. Player 1 goes first. The first person to get the running total to 25 wins. With perfect play, is Player 1 going to win, or is Player 2 going to win? Figure out the optimal strategy for the winner. Show your work.

Solutions

Expert Solution

Lets try to solve the problem from backward calculations.

A and B are 2 players.

Say that A moves first, then B moves and so on.

The person who takes the running total to 25 wins.

That means the running total before this hand should be somewhere between 15-24. (Cause they can choose between 1-10)

So, the player who takes the running total to exactly 14 will win the tournament. (because the next person should choose between 0-10, and that choice will take the total between 15-24)

Now, if A moves first and choose any number between 4-10 then A will loose. (As B can take the total to 14 easily)

So A will choose 3.

Now, lets iterate

A choose 3

B chooses any number between 1-10 (say x) (running total is between 4-13)

Depending upon the choice of B, A will choose a number (11 - x) to make the running total exactly 14

Now whatever B choose (say y), running total will be between 15-25

Depending upon the choice of B, A will choose a number (11 - y) to make the running total exactly 25

So, the one who moves first will win the game.

2)

Player 1 : A : Can choose between 1 to 5

Player 2 : B : Can choose between 1 to 6

A moves first. Player to get running total to 25 wins.

Again, lets try to solve this in reverse direction.

A will win if running total before A's move is between 20-24.

If running total after A's move is 19 then B will win, because B can choose 6.

If running total after A's move is 18 then B will win, because B can choose 1 and running total will be 19, then A cant take it to 25, because A cannot choose 6.

So, B wins the game, if B can make the running total 19. So, before B's move the running total should be between 13-18. Therefore, B wants to take it to 12-13 and B will win the tournament.

So, B wins the game, if B can make the running total 12-13. So, before B's move the running total should be between 6-11. Therefore B wants to take it to 5 and B will win the tournament.

Suppose A will choose 1, B can choose 4 - running total 5.

Suppose A will choose 2, B can choose 3 - running total 5.

Suppose A will choose 3, B can choose 2 - running total 5.

Suppose A will choose 4, B can choose 1 - running total 5.

Running total 5, Now A's turn,

Suppose A will choose 1, B can choose 6 - running total 12.

Suppose A will choose 2, B can choose 5 - running total 12.

Suppose A will choose 3, B can choose 4 - running total 12.

Suppose A will choose 4, B can choose 3 - running total 12.

Suppose A will choose 5, B can choose 2 - running total 12.

Running total 12, Now A's turn,

Suppose A will choose 1, B can choose 6 - running total 19.

Suppose A will choose 2, B can choose 5 - running total 19.

Suppose A will choose 3, B can choose 4 - running total 19.

Suppose A will choose 4, B can choose 3 - running total 19.

Suppose A will choose 5, B can choose 2 - running total 19.

Running total 19, Now A's turn,

Suppose A will choose 1, B can choose 5 - running total 25.

Suppose A will choose 2, B can choose 4 - running total 25.

Suppose A will choose 3, B can choose 3 - running total 25.

Suppose A will choose 4, B can choose 2 - running total 25.

Suppose A will choose 5, B can choose 1 - running total 25

B wins in all above scenarios, that is if A chooses 1-4 first.

So, A will choose 5 in the first move

Even if A will choose 5, B can choose 1, running total 6

A can choose between 1-5 and can make running total 7-11.

So, B can again take running total to 12, and will win.

So, B will win in any scenario.


Related Solutions

Two people are playing an exciting game in which they take turns removing marbles from a...
Two people are playing an exciting game in which they take turns removing marbles from a bag. At the beginning of the game, this bag contains some red marbles and some blue marbles. The bag is transparent so at any time during the game, the players know exactly how many red and how many blue marbles are in the bag. The players alternate taking turns. On a player’s turn, he or she must remove some marbles from the bag. The...
Consider a game in which two players, Fred and Barney, take turns removing matchsticks from a...
Consider a game in which two players, Fred and Barney, take turns removing matchsticks from a pile. They start with 21 matchsticks, and Fred goes first. On each turn, each player may remove either one, two, or three matchsticks. The player to remove the last matchstick wins the game. (a) Suppose there are only 5 matchsticks left, and it is Fred’s turn. What move should Fred make to guarantee himself victory? Explain your reasoning. (b) Suppose there are 10 matchsticks...
There are 21 pennies on a table between two players. The two players take turns removing...
There are 21 pennies on a table between two players. The two players take turns removing either 1, 2 or 3 pennies at a time. The player who takes the last penny loses. Use backward induction to come up with a strategy that the player who takes the second turn in the game can use to guarantee that she wins the game.
Suppose that two players are playing the following game. Player 1 can choose either Top or...
Suppose that two players are playing the following game. Player 1 can choose either Top or Bottom, and Player 2 can choose either Left or Right. The payoffs are given in the following table: player 2: left right   player 1 : Top: (1,2) (2,4) bottom: (3,4) (0,3) where the number on the left is the payoff to Player 1, and the number on the right is the payoff to Player 2. A) (2 points) Does Player 1 have a dominant...
In this game, two players sit in front of a pile of 100 stones. They take...
In this game, two players sit in front of a pile of 100 stones. They take turns, each removing between 1 and 5 stones (assuming there are at least 5 stones left in the pile). The person who removes the last stone(s) wins. Write a program to play this game. This may seem tricky, so break it down into parts. Like many programs, we have to use nested loops (one loop inside another). In the outermost loop, we want to...
You are playing a version of the roulette game, where the pockets are from 0 to...
You are playing a version of the roulette game, where the pockets are from 0 to 10 and even numbers are red and odd numbers are black (0 is green). You spin 3 times and add up the values you see. What is the probability that you get a total of 15 given on the first spin you spin a 2? What about a 3? Solve by simulation and analytically.
Hotelling’s location game. Recall the voting game discussed in class. There are two candidates, each of...
Hotelling’s location game. Recall the voting game discussed in class. There are two candidates, each of whom chooses a position from the set S = (1,2,...10). The voters are equally distributed across these ten positions. Voters vote for the candidate whose position is closest to theirs. If the two candidates are equidistant from a given position, the voters at that position split their votes equally. First, unlike in the game analyzed in class, assume that both candidates only care about...
Two players take turns taking sticks from a pile of 16 sticks. Each player can take...
Two players take turns taking sticks from a pile of 16 sticks. Each player can take at most 3 sticks and at least 1 stick at each turn. Whoever takes the final stick wins the game. Describe in words the optimal strategy for each player. Is there a first-mover advantage in this game? Is there a second-mover advantage?
Two players (player A and player B) are playing a game against each other repeatedly until...
Two players (player A and player B) are playing a game against each other repeatedly until one is bankrupt. When a player wins a game they take $1 from the other player. All plays of the game are independent and identical. Suppose player A starts with $6 and player B starts with $6. If player A wins a game with probability 0.5, what is the probability the game ends (someone loses all their money) on exactly the 10th play of...
(10 marks) Two players (player A and player B) are playing a game against each other...
Two players (player A and player B) are playing a game against each other repeatedly until one is bankrupt. When a player wins a game they take $1 from the other player. All plays of the game are independent and identical. a) Suppose player A starts with $2 and player B starts with $1. If player A wins a game with probability p, what is the probability that player A wins all the money? b) Suppose player A starts with...
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT