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September 2024 term · Game Theory and Strategy · BSMS4023

Game Theory and Strategy Quiz 1: 27 October 2024 (September 2024 term)

The IIT Madras BS Game Theory and Strategy (Game Theory) Quiz 1 paper sat on 27 Oct 2024, in the September 2024 term: 20 questions for 25 marks in 120 minutes. Every question is below with its answer. Take it as a timed mock test to be marked, or read it through first.

Questions
20
Marks
25
Duration
120 min
MCQ
16
Numerical
4

Updated

Official paper: IIT M DEGREE AN EXAM QDB2 27 Oct 2024 · No negative marking.

Question 1

+1 markOne correct option

An item is up for auction. Player 1 values the item at 3 while player 2 values the item at 5. Each player can bid either 0, 1 or 2. If player i bids more than player j then i wins the good and pays his bid, while the loser does not pay. If both players bid the same amount, then a coin is tossed to determine who the winner is, who gets the good and pays his bid while the loser pays nothing. Formulate the game in matrix form and answer the given subquestions.

Which player does not have strictly dominated strategy?

  1. A

    Player 1

  2. B

    Player 2

  3. C

    None

Show answer

Correct answer

  • A

    Player 1

Question 2

+2 marksOne correct option

An item is up for auction. Player 1 values the item at 3 while player 2 values the item at 5. Each player can bid either 0, 1 or 2. If player i bids more than player j then i wins the good and pays his bid, while the loser does not pay. If both players bid the same amount, then a coin is tossed to determine who the winner is, who gets the good and pays his bid while the loser pays nothing. Formulate the game in matrix form and answer the given subquestions.

Which strategies survive Iterated Elimination of Strictly Dominated Strategy?

  1. A

    (0, 0)

  2. B

    (1, 1)

  3. C

    (2, 2)

  4. D

    None

Show answer

Correct answer

  • C

    (2, 2)

Question 3

+1 markOne correct option

Determined to crack down on the drug trade, a city mayor puts more officers out on patrol to disrupt the business of drug dealers. A drug dealer in a neighborhood can work his trade either on a street corner or in the park. Each day, he decides where to set up shop, knowing that word about his location will travel among users. Because a good snitch is lacking, word does not travel to the police. The police officer on the beat then needs to decide whether she will patrol the park or the street corner, while not knowing where the drug dealer is hanging out that day. The decision of the officer and the dealer determine the extent of drug trades that day. Let suppose the total number of potential trades in the market is 100. A dealer's payoff is determined by the number of trades he consummates, while the officer’s payoff is based on the number of trades she disrupts. The table below illustrates the payoffs for both parties according to their respective strategies in the game.

Based on the above data, answer the given subquestions.

Choose the correct statement

  1. A

    There is a unique Nash equilibrium in pure strategy

  2. B

    There are finitely many Nash equilibria in this game in pure strategy

  3. C

    There is no Nash equilibrium in this game in pure strategy

  4. D

    None

Show answer

Correct answer

  • C

    There is no Nash equilibrium in this game in pure strategy

Question 4

+1 markOne correct option

Determined to crack down on the drug trade, a city mayor puts more officers out on patrol to disrupt the business of drug dealers. A drug dealer in a neighborhood can work his trade either on a street corner or in the park. Each day, he decides where to set up shop, knowing that word about his location will travel among users. Because a good snitch is lacking, word does not travel to the police. The police officer on the beat then needs to decide whether she will patrol the park or the street corner, while not knowing where the drug dealer is hanging out that day. The decision of the officer and the dealer determine the extent of drug trades that day. Let suppose the total number of potential trades in the market is 100. A dealer's payoff is determined by the number of trades he consummates, while the officer’s payoff is based on the number of trades she disrupts. The table below illustrates the payoffs for both parties according to their respective strategies in the game.

Based on the above data, answer the given subquestions.

Choose the correct statement

  1. A

    There is a unique Nash equilibrium in this game

  2. B

    There are finitely many Nash equilibria in this game

  3. C

    There is no Nash equilibrium in this game

  4. D

    None

Show answer

Correct answer

  • A

    There is a unique Nash equilibrium in this game

Question 5

+1 markNumerical answer

Determined to crack down on the drug trade, a city mayor puts more officers out on patrol to disrupt the business of drug dealers. A drug dealer in a neighborhood can work his trade either on a street corner or in the park. Each day, he decides where to set up shop, knowing that word about his location will travel among users. Because a good snitch is lacking, word does not travel to the police. The police officer on the beat then needs to decide whether she will patrol the park or the street corner, while not knowing where the drug dealer is hanging out that day. The decision of the officer and the dealer determine the extent of drug trades that day. Let suppose the total number of potential trades in the market is 100. A dealer's payoff is determined by the number of trades he consummates, while the officer’s payoff is based on the number of trades she disrupts. The table below illustrates the payoffs for both parties according to their respective strategies in the game.

Based on the above data, answer the given subquestions.

If the randomization probability of a police officer for patrolling the streets is p/13, then p =__________

Show answer

Correct answer: 5

Question 6

+1 markNumerical answer

Determined to crack down on the drug trade, a city mayor puts more officers out on patrol to disrupt the business of drug dealers. A drug dealer in a neighborhood can work his trade either on a street corner or in the park. Each day, he decides where to set up shop, knowing that word about his location will travel among users. Because a good snitch is lacking, word does not travel to the police. The police officer on the beat then needs to decide whether she will patrol the park or the street corner, while not knowing where the drug dealer is hanging out that day. The decision of the officer and the dealer determine the extent of drug trades that day. Let suppose the total number of potential trades in the market is 100. A dealer's payoff is determined by the number of trades he consummates, while the officer’s payoff is based on the number of trades she disrupts. The table below illustrates the payoffs for both parties according to their respective strategies in the game.

Based on the above data, answer the given subquestions.

If the randomization probability of a police officer for patrolling the park is q/13, then q = ________

Show answer

Correct answer: 8

Question 7

+1 markNumerical answer

Determined to crack down on the drug trade, a city mayor puts more officers out on patrol to disrupt the business of drug dealers. A drug dealer in a neighborhood can work his trade either on a street corner or in the park. Each day, he decides where to set up shop, knowing that word about his location will travel among users. Because a good snitch is lacking, word does not travel to the police. The police officer on the beat then needs to decide whether she will patrol the park or the street corner, while not knowing where the drug dealer is hanging out that day. The decision of the officer and the dealer determine the extent of drug trades that day. Let suppose the total number of potential trades in the market is 100. A dealer's payoff is determined by the number of trades he consummates, while the officer’s payoff is based on the number of trades she disrupts. The table below illustrates the payoffs for both parties according to their respective strategies in the game.

Based on the above data, answer the given subquestions.

If the randomization probability of the drug dealer choosing street is r/13, then r =_______________

Show answer

Correct answer: 6

Question 8

+1 markNumerical answer

Determined to crack down on the drug trade, a city mayor puts more officers out on patrol to disrupt the business of drug dealers. A drug dealer in a neighborhood can work his trade either on a street corner or in the park. Each day, he decides where to set up shop, knowing that word about his location will travel among users. Because a good snitch is lacking, word does not travel to the police. The police officer on the beat then needs to decide whether she will patrol the park or the street corner, while not knowing where the drug dealer is hanging out that day. The decision of the officer and the dealer determine the extent of drug trades that day. Let suppose the total number of potential trades in the market is 100. A dealer's payoff is determined by the number of trades he consummates, while the officer’s payoff is based on the number of trades she disrupts. The table below illustrates the payoffs for both parties according to their respective strategies in the game.

Based on the above data, answer the given subquestions.

If the randomization probability of the drug dealer choosing park is s/13, then s = _____________

Show answer

Correct answer: 7

Question 9

+1 markOne correct option

Consider a two-player game in which player 1 can choose A or B. The game ends if he chooses A while it continues to player 2 if he chooses B. Player 2 can either choose C or D, with the game ending after C and continuing again with player 1 after D. Player 1 then can choose E or F, and then the game ends after each of these choices.
Imagine that the payoffs following choice A by player 1 are (2, 0), following C by player 2 are (3, 1), following E by player 1 are (0, 0) and following F by player 1 are (1, 2)
Model this as an extensive form game and answer the given subquestions:

This is a game of

  1. A

    Perfect information

  2. B

    Imperfect information

  3. C

    None

  4. D

    Can’t be determined

Show answer

Correct answer

  • A

    Perfect information

Question 10

+1 markOne correct option

Consider a two-player game in which player 1 can choose A or B. The game ends if he chooses A while it continues to player 2 if he chooses B. Player 2 can either choose C or D, with the game ending after C and continuing again with player 1 after D. Player 1 then can choose E or F, and then the game ends after each of these choices.
Imagine that the payoffs following choice A by player 1 are (2, 0), following C by player 2 are (3, 1), following E by player 1 are (0, 0) and following F by player 1 are (1, 2)
Model this as an extensive form game and answer the given subquestions:

How many terminal nodes does this game have?

  1. A

    3

  2. B

    2

  3. C

    4

  4. D

    5

Show answer

Correct answer

  • C

    4

Question 11

+1 markOne correct option

Consider a two-player game in which player 1 can choose A or B. The game ends if he chooses A while it continues to player 2 if he chooses B. Player 2 can either choose C or D, with the game ending after C and continuing again with player 1 after D. Player 1 then can choose E or F, and then the game ends after each of these choices.
Imagine that the payoffs following choice A by player 1 are (2, 0), following C by player 2 are (3, 1), following E by player 1 are (0, 0) and following F by player 1 are (1, 2)
Model this as an extensive form game and answer the given subquestions:

How many information sets does this game have?

  1. A

    2

  2. B

    3

  3. C

    4

  4. D

    1

Show answer

Correct answer

  • B

    3

Question 12

+1 markOne correct option

Consider a two-player game in which player 1 can choose A or B. The game ends if he chooses A while it continues to player 2 if he chooses B. Player 2 can either choose C or D, with the game ending after C and continuing again with player 1 after D. Player 1 then can choose E or F, and then the game ends after each of these choices.
Imagine that the payoffs following choice A by player 1 are (2, 0), following C by player 2 are (3, 1), following E by player 1 are (0, 0) and following F by player 1 are (1, 2)
Model this as an extensive form game and answer the given subquestions:

How many pure strategies does player 1 have?

  1. A

    1

  2. B

    2

  3. C

    3

  4. D

    4

Show answer

Correct answer

  • D

    4

Question 13

+1 markOne correct option

Consider a two-player game in which player 1 can choose A or B. The game ends if he chooses A while it continues to player 2 if he chooses B. Player 2 can either choose C or D, with the game ending after C and continuing again with player 1 after D. Player 1 then can choose E or F, and then the game ends after each of these choices.
Imagine that the payoffs following choice A by player 1 are (2, 0), following C by player 2 are (3, 1), following E by player 1 are (0, 0) and following F by player 1 are (1, 2)
Model this as an extensive form game and answer the given subquestions:

How many pure strategies does player 2 have?

  1. A

    1

  2. B

    2

  3. C

    3

  4. D

    4

Show answer

Correct answer

  • B

    2

Question 14

+1 markOne correct option

Consider a two-player game in which player 1 can choose A or B. The game ends if he chooses A while it continues to player 2 if he chooses B. Player 2 can either choose C or D, with the game ending after C and continuing again with player 1 after D. Player 1 then can choose E or F, and then the game ends after each of these choices.
Imagine that the payoffs following choice A by player 1 are (2, 0), following C by player 2 are (3, 1), following E by player 1 are (0, 0) and following F by player 1 are (1, 2)
Model this as an extensive form game and answer the given subquestions:

How many pure strategy Nash equilibria does this game have?

  1. A

    1

  2. B

    2

  3. C

    3

  4. D

    4

Show answer

Correct answer

  • C

    3

Question 15

+1 markOne correct option

Consider a two-player game in which player 1 can choose A or B. The game ends if he chooses A while it continues to player 2 if he chooses B. Player 2 can either choose C or D, with the game ending after C and continuing again with player 1 after D. Player 1 then can choose E or F, and then the game ends after each of these choices.
Imagine that the payoffs following choice A by player 1 are (2, 0), following C by player 2 are (3, 1), following E by player 1 are (0, 0) and following F by player 1 are (1, 2)
Model this as an extensive form game and answer the given subquestions:

Which one of the Nash equilibria is also a subgame perfect equilibrium?

  1. A

    (AE, D)

  2. B

    (AF, D)

  3. C

    (BE, C)

  4. D

    (BF, C)

Show answer

Correct answer

  • B

    (AF, D)

Question 16

+1 markOne correct option

Consider a two-player game in which player 1 can choose A or B. The game ends if he chooses A while it continues to player 2 if he chooses B. Player 2 can either choose C or D, with the game ending after C and continuing again with player 1 after D. Player 1 then can choose E or F, and then the game ends after each of these choices.
Imagine that the payoffs following choice A by player 1 are (2, 0), following C by player 2 are (3, 1), following E by player 1 are (0, 0) and following F by player 1 are (1, 2)
Model this as an extensive form game and answer the given subquestions:

No. of sub games this game has

  1. A

    1

  2. B

    2

  3. C

    3

  4. D

    4

Show answer

Correct answer

  • C

    3

Question 17

+2 marksOne correct option

(Choosing a route) Four people must drive from A to B at the same time. Two routes are available, one via X and one via Y (Refer to the left panel of following Figure). The roads from A to X, and from Y to B are both short and narrow; in each case, one car takes 6 minutes, and each additional car increases the travel time per car by 3 minutes. (If two cars drive from A to X, for example, each car takes 9 minutes.) The roads from A to Y, and from X to B are long and wide; on A to Y one car takes 20 minutes, and each additional car increases the travel time per car by 1 minute; on X to B one car takes 20 minutes, and each additional car increases the travel time per car by 0.9 minutes. Formulate this situation as a strategic game and answer the given subquestions.

Choose the correct alternative

  1. A

    In Nash equilibrium two people take each route

  2. B

    For the NE action profile, each person’s travel time is either 29.9 or 30 minutes

  3. C

    In Nash equilibrium two people take each route and For the NE action profile, each person’s travel time is either 29.9 or 30 minutes

  4. D

    None

Show answer

Correct answer

  • C

    In Nash equilibrium two people take each route and For the NE action profile, each person’s travel time is either 29.9 or 30 minutes

Question 18

+2 marksOne correct option

(Choosing a route) Four people must drive from A to B at the same time. Two routes are available, one via X and one via Y (Refer to the left panel of following Figure). The roads from A to X, and from Y to B are both short and narrow; in each case, one car takes 6 minutes, and each additional car increases the travel time per car by 3 minutes. (If two cars drive from A to X, for example, each car takes 9 minutes.) The roads from A to Y, and from X to B are long and wide; on A to Y one car takes 20 minutes, and each additional car increases the travel time per car by 1 minute; on X to B one car takes 20 minutes, and each additional car increases the travel time per car by 0.9 minutes. Formulate this situation as a strategic game and answer the given subquestions.

Now suppose that a relatively short, wide road is built from X to Y, giving each person four options for travel from A to B: A–X–B, A–Y–B, A–X–Y–B, and A–Y– X–B (As shown in the right panel of the given figure). Assume that a person who takes A–X–Y–B travels the A–X portion at the same time as someone who takes A–X–B, and the Y–B portion at the same time as someone who takes A–Y–B. (Think of there being constant flows of traffic.) On the road between X and Y, one car takes 7 minutes and each additional car increases the travel time per car by 1 minute. Find the Nash equilibrium in this new situation and answer the questions.
Choose the correct alternative

  1. A

    In any Nash equilibrium, one person takes A–X–B, two people take A–X–Y–B, and one person takes A–Y–B

  2. B

    In this equilibrium profile, each person’s travel time is 36 minutes

  3. C

    In any Nash equilibrium, one person takes A–X–B, two people take A–X–Y–B, and one person takes A–Y–B and In this equilibrium profile, each person’s travel time is 36 minutes

  4. D

    None

Show answer

Correct answer

  • A

    In any Nash equilibrium, one person takes A–X–B, two people take A–X–Y–B, and one person takes A–Y–B

Question 19

+2 marksOne correct option

Based on the above data, answer the given subquestions.

  1. A
  2. B
  3. C
  4. D
Show answer

Correct answer

  • C

Question 20

+2 marksOne correct option

Based on the above data, answer the given subquestions.

Choose the correct alternative

  1. A
  2. B
  3. C
  4. D
Show answer

Correct answer

  • C