Question 1
Consider the following prisoners’ dilemma game and answer the given subquestions
Unique NE of this game is
(Defect, Defect )
(Cooperate, Cooperate )
Both
None

The IIT Madras BS Game Theory and Strategy (Game Theory) Quiz 2 paper sat on 16 Aug 2026, in the May 2026 term: 31 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.
Consider the following prisoners’ dilemma game and answer the given subquestions
Unique NE of this game is
(Defect, Defect )
(Cooperate, Cooperate )
Both
None
Correct answer
(Defect, Defect )
Consider the following prisoners’ dilemma game and answer the given subquestions
Suppose, this game is repeatedly played finite times
In the last period Cooperate is a dominant strategy irrespective of history of the game
In the last period Defect is a dominant strategy irrespective of history of the game
In the last period Cooperate is a dominant strategy for a particular game history
In the last period Defect is a dominant strategy for a particular game history
Correct answer
In the last period Defect is a dominant strategy irrespective of history of the game
Consider the following prisoners’ dilemma game and answer the given subquestions
Suppose, this game is repeatedly played for 2 times and in the first period, if both players choose their dominant strategy. Derive the payoff matrix for second period and find out the value of following unknowns that represent payoff at the end of second period:
j= ____________
Correct answer: 7
Consider the following prisoners’ dilemma game and answer the given subquestions
Suppose, this game is repeatedly played for 2 times and in the first period, if both players choose their dominant strategy. Derive the payoff matrix for second period and find out the value of following unknowns that represent payoff at the end of second period:
l=____________
Correct answer: 4
Consider the following prisoners’ dilemma game and answer the given subquestions
Suppose, this game is repeatedly played for 2 times and in the first period, if both players choose their dominant strategy. Derive the payoff matrix for second period and find out the value of following unknowns that represent payoff at the end of second period:
m=____________
Correct answer: 8
Consider the following prisoners’ dilemma game and answer the given subquestions
Suppose, this game is repeatedly played for 2 times and in the first period, if both players choose their dominant strategy. Derive the payoff matrix for second period and find out the value of following unknowns that represent payoff at the end of second period:
r =____________
Correct answer: 6
(Bayesian Game ) Consider a variant of the situation modelled by Battle of sexes (BOS) (as discussed in lectures) in which player 1 is unsure whether player 2 prefers to go out with her or prefers to avoid her, whereas player 2, as before, knows player 1’s preferences. Specifically, suppose player 1 thinks that with probability 1/2 player 2 wants to go out with her, and with probability 1/2 player 2 wants to avoid her. The situation is depicted in the following matrix of a static game with incomplete information:
With the help of this game matrix, we may come up with the following table depicting expected payoff of player 1 corresponding to different actions of both types of player 2.
Based on the above data, answer the given subquestions.
Find out the value of following unknown: a = __________
Correct answer: 1
(Bayesian Game ) Consider a variant of the situation modelled by Battle of sexes (BOS) (as discussed in lectures) in which player 1 is unsure whether player 2 prefers to go out with her or prefers to avoid her, whereas player 2, as before, knows player 1’s preferences. Specifically, suppose player 1 thinks that with probability 1/2 player 2 wants to go out with her, and with probability 1/2 player 2 wants to avoid her. The situation is depicted in the following matrix of a static game with incomplete information:
With the help of this game matrix, we may come up with the following table depicting expected payoff of player 1 corresponding to different actions of both types of player 2.
Based on the above data, answer the given subquestions.
Find out the value of following unknown: b =__________
Correct answer: 0.5
(Bayesian Game ) Consider a variant of the situation modelled by Battle of sexes (BOS) (as discussed in lectures) in which player 1 is unsure whether player 2 prefers to go out with her or prefers to avoid her, whereas player 2, as before, knows player 1’s preferences. Specifically, suppose player 1 thinks that with probability 1/2 player 2 wants to go out with her, and with probability 1/2 player 2 wants to avoid her. The situation is depicted in the following matrix of a static game with incomplete information:
With the help of this game matrix, we may come up with the following table depicting expected payoff of player 1 corresponding to different actions of both types of player 2.
Based on the above data, answer the given subquestions.
Find out the value of following unknown: c =__________
Correct answer: 0.5
(Bayesian Game ) Consider a variant of the situation modelled by Battle of sexes (BOS) (as discussed in lectures) in which player 1 is unsure whether player 2 prefers to go out with her or prefers to avoid her, whereas player 2, as before, knows player 1’s preferences. Specifically, suppose player 1 thinks that with probability 1/2 player 2 wants to go out with her, and with probability 1/2 player 2 wants to avoid her. The situation is depicted in the following matrix of a static game with incomplete information:
With the help of this game matrix, we may come up with the following table depicting expected payoff of player 1 corresponding to different actions of both types of player 2.
Based on the above data, answer the given subquestions.
Find out the value of following unknown: d =__________
Correct answer: 0
(Bayesian Game ) Consider a variant of the situation modelled by Battle of sexes (BOS) (as discussed in lectures) in which player 1 is unsure whether player 2 prefers to go out with her or prefers to avoid her, whereas player 2, as before, knows player 1’s preferences. Specifically, suppose player 1 thinks that with probability 1/2 player 2 wants to go out with her, and with probability 1/2 player 2 wants to avoid her. The situation is depicted in the following matrix of a static game with incomplete information:
With the help of this game matrix, we may come up with the following table depicting expected payoff of player 1 corresponding to different actions of both types of player 2.
Based on the above data, answer the given subquestions.
Find out the value of following unknown: p =__________
Correct answer: 0
(Bayesian Game ) Consider a variant of the situation modelled by Battle of sexes (BOS) (as discussed in lectures) in which player 1 is unsure whether player 2 prefers to go out with her or prefers to avoid her, whereas player 2, as before, knows player 1’s preferences. Specifically, suppose player 1 thinks that with probability 1/2 player 2 wants to go out with her, and with probability 1/2 player 2 wants to avoid her. The situation is depicted in the following matrix of a static game with incomplete information:
With the help of this game matrix, we may come up with the following table depicting expected payoff of player 1 corresponding to different actions of both types of player 2.
Based on the above data, answer the given subquestions.
Find out the value of following unknown: q =__________
Correct answer: 1
(Bayesian Game ) Consider a variant of the situation modelled by Battle of sexes (BOS) (as discussed in lectures) in which player 1 is unsure whether player 2 prefers to go out with her or prefers to avoid her, whereas player 2, as before, knows player 1’s preferences. Specifically, suppose player 1 thinks that with probability 1/2 player 2 wants to go out with her, and with probability 1/2 player 2 wants to avoid her. The situation is depicted in the following matrix of a static game with incomplete information:
With the help of this game matrix, we may come up with the following table depicting expected payoff of player 1 corresponding to different actions of both types of player 2.
Based on the above data, answer the given subquestions.
Find out the value of following unknown: r =__________
Correct answer: 1
(Bayesian Game ) Consider a variant of the situation modelled by Battle of sexes (BOS) (as discussed in lectures) in which player 1 is unsure whether player 2 prefers to go out with her or prefers to avoid her, whereas player 2, as before, knows player 1’s preferences. Specifically, suppose player 1 thinks that with probability 1/2 player 2 wants to go out with her, and with probability 1/2 player 2 wants to avoid her. The situation is depicted in the following matrix of a static game with incomplete information:
With the help of this game matrix, we may come up with the following table depicting expected payoff of player 1 corresponding to different actions of both types of player 2.
Based on the above data, answer the given subquestions.
Find out the value of following unknown: t =__________
Correct answer: 2
(Bayesian Game ) Consider a variant of the situation modelled by Battle of sexes (BOS) (as discussed in lectures) in which player 1 is unsure whether player 2 prefers to go out with her or prefers to avoid her, whereas player 2, as before, knows player 1’s preferences. Specifically, suppose player 1 thinks that with probability 1/2 player 2 wants to go out with her, and with probability 1/2 player 2 wants to avoid her. The situation is depicted in the following matrix of a static game with incomplete information:
With the help of this game matrix, we may come up with the following table depicting expected payoff of player 1 corresponding to different actions of both types of player 2.
Based on the above data, answer the given subquestions.
What is the Bayesian Nash equilibrium Strategy of player 1 in this game?
B
S
Either of the two
None
Correct answer
S
(Bayesian Game ) Consider a variant of the situation modelled by Battle of sexes (BOS) (as discussed in lectures) in which player 1 is unsure whether player 2 prefers to go out with her or prefers to avoid her, whereas player 2, as before, knows player 1’s preferences. Specifically, suppose player 1 thinks that with probability 1/2 player 2 wants to go out with her, and with probability 1/2 player 2 wants to avoid her. The situation is depicted in the following matrix of a static game with incomplete information:
With the help of this game matrix, we may come up with the following table depicting expected payoff of player 1 corresponding to different actions of both types of player 2.
Based on the above data, answer the given subquestions.
What is the Bayesian Nash equilibrium Strategy of both types of player 2 in this game?
(B,S)
(B,B)
(S,B)
(S,S)
Correct answer
(S,B)
Consider the following game matrix:
Based on the above data, answer the given subquestions.
Choose the correct alternative
(Slow, Slow) is an NE
(Slow, Fast) is an NE
Both
None
Correct answer
(Slow, Slow) is an NE
Consider the following game matrix:
Based on the above data, answer the given subquestions.
ESS in this game is
Slow
Fast
Both
None
Correct answer
Both
Given the following preference structure, find a stable matching system using the Gale- Shapley algorithm when the men propose.
Based on the above data, answer the given subquestions.
Ms. A will be paired with
a
c
d
b
Correct answer
c
Given the following preference structure, find a stable matching system using the Gale- Shapley algorithm when the men propose.
Based on the above data, answer the given subquestions.
Ms. B will be paired with
b
c
a
d
Correct answer
a
Given the following preference structure, find a stable matching system using the Gale- Shapley algorithm when the men propose.
Based on the above data, answer the given subquestions.
Ms. C will be paired with
b
d
c
a
Correct answer
b
Given the following preference structure, find a stable matching system using the Gale- Shapley algorithm when the men propose.
Based on the above data, answer the given subquestions.
Ms. D will be paired with
a
d
b
c
Correct answer
d
Consider the example of cascade discussed in the lecture but with a modification that now the urn is containing either 4 blue balls and 2 red balls or 4 red balls and 2 blue balls with equal probability. That simply means that the urn is equally likely to be blue-majority urn or red-majority urn. We assume everyone hears what the previous individuals report and get their own private signal by randomly drawing one ball from the urn.
Based on the above data, answer the given subquestions.
Suppose one ball is picked from the red majority urn. What is the probability that the ball is blue?
1/3
1/4
1/2
2/3
Correct answer
1/3
Consider the example of cascade discussed in the lecture but with a modification that now the urn is containing either 4 blue balls and 2 red balls or 4 red balls and 2 blue balls with equal probability. That simply means that the urn is equally likely to be blue-majority urn or red-majority urn. We assume everyone hears what the previous individuals report and get their own private signal by randomly drawing one ball from the urn.
Based on the above data, answer the given subquestions.
What is the probability that the urn is red majority if the first student draws a red ball?
2/4
1/3
2/3
1/4
Correct answer
2/3
Consider the example of cascade discussed in the lecture but with a modification that now the urn is containing either 4 blue balls and 2 red balls or 4 red balls and 2 blue balls with equal probability. That simply means that the urn is equally likely to be blue-majority urn or red-majority urn. We assume everyone hears what the previous individuals report and get their own private signal by randomly drawing one ball from the urn.
Based on the above data, answer the given subquestions.
Now suppose, the first three students draw the ball in the sequence (Red, Red, Blue).
What is the probability of getting this sequence if the urn is a blue majority urn?
2/27
4/27
1/27
6/27
Correct answer
2/27
Consider the example of cascade discussed in the lecture but with a modification that now the urn is containing either 4 blue balls and 2 red balls or 4 red balls and 2 blue balls with equal probability. That simply means that the urn is equally likely to be blue-majority urn or red-majority urn. We assume everyone hears what the previous individuals report and get their own private signal by randomly drawing one ball from the urn.
Based on the above data, answer the given subquestions.
Now suppose, the first three students draw the ball in the sequence (Red, Red, Blue).
What is the probability of getting this sequence if the urn is a red majority urn?
1/27
4/27
6/27
2/27
Correct answer
4/27
Consider the example of cascade discussed in the lecture but with a modification that now the urn is containing either 4 blue balls and 2 red balls or 4 red balls and 2 blue balls with equal probability. That simply means that the urn is equally likely to be blue-majority urn or red-majority urn. We assume everyone hears what the previous individuals report and get their own private signal by randomly drawing one ball from the urn.
Based on the above data, answer the given subquestions.
Now suppose, the first three students draw the ball in the sequence (Red, Red, Blue).
What is the total probability of getting this sequence?
1/27
1/9
4/27
4/9
Correct answer
1/9
Consider the example of cascade discussed in the lecture but with a modification that now the urn is containing either 4 blue balls and 2 red balls or 4 red balls and 2 blue balls with equal probability. That simply means that the urn is equally likely to be blue-majority urn or red-majority urn. We assume everyone hears what the previous individuals report and get their own private signal by randomly drawing one ball from the urn.
Based on the above data, answer the given subquestions.
Now suppose, the first three students draw the ball in the sequence (Red, Red, Blue).
What is the probability of the urn being red majority in this scenario?
3/6
1/3
2/3
1/6
Correct answer
2/3
Grim Trigger: Consider the infinitely repeated game with discount factor δ<1 of the following variant of the Prisoner’s Dilemma:
Based on the above data, answer the given subquestions.
Unique NE of this game is
(T,L)
(B,R)
(M,C)
None
Correct answer
(B,R)
Grim Trigger: Consider the infinitely repeated game with discount factor δ<1 of the following variant of the Prisoner’s Dilemma:
Based on the above data, answer the given subquestions.
For which values of the discount factor δ can the players support the pair of actions (M,C) played in every period?
(δ ≥ 1/5)
(δ ≥ 1/3)
(δ ≥ 3/7)
(δ ≥ 1/2)
Correct answer
(δ ≥ 1/5)
Grim Trigger: Consider the infinitely repeated game with discount factor δ<1 of the following variant of the Prisoner’s Dilemma:
Based on the above data, answer the given subquestions.
For which values of the discount factor δ can the players support the pair of actions (T,L) played in every period?
(δ ≥ 1/7)
(δ ≥ 0)
(δ ≥ 1/4)
(δ ≥ 1/2)
Correct answer
(δ ≥ 1/4)