Teams A and B are in a five-game playoff series; the team that wins th

gamomaniea1

gamomaniea1

Answered question

2021-11-15

Teams A and B are in a five-game playoff matchup; the team that wins three games is the team that wins the series. Assuming that both teams are evenly matched (i.e., the probability of winning each game is 50/50). 
(a) Team A won the first game. What is the probability that team B will win the series? 
(b) Continue to assume that Team A has already won one game, but the teams are not evenly matched. Assume that B is a better team. It’s better in that its probability of beating Team A in any one game is .55. What is the probability that Team B will win the series?

Answer & Explanation

Mary Darby

Mary Darby

Beginner2021-11-16Added 11 answers

Step 1
Given: Teams A and B are in a five-game playoff series; the team that wins three games is the team that wins the series. Assume that both teams are evenly matched (i.e.the probability of winning each game is 50/50).
Probability of A winning a game =0.5
Probability of B winning a game =0.5.
Let X be the random variable representing the number of games won by Team B.
(a) Team A won the first game, the probability that team B will win the series:
As team A has won the first game therefore for team B to win the series it has to win either 3 out of the next 4 games or 4 out of the next 4 games. The required probability follows a binomial distribution with n=4,p=0.5.
Step 2
Therefore, the probability of B winning will be P(X=3)+P(X=4).
P(B wng)=P(X=3)+P(X=4)
=4C3(0.5)3(10.5)43+4C4(0.5)4(10.5)44
=4C3(0.5)3(0.5)1+4C4(0.5)4(0.5)0
=4×0.0625+0.0625
=0.25+0.0625
=0.3125
Thus, if Team A won the first game the probability that team B will win the series is 0.3125.
(b) Team A has already won one game, the probability of team B winning is 0.55 the probability that team B will win the series:
The probability of Team B winning is =0.55.
As team A has won the first game therefore for team B to win the series it has to win either 3 out of the next 4 games or 4 out of the next 4 games. The required probability follows a binomial distribution with n=4,p=0.55.
Therefore, the probability of B winning will be P(X=3)+P(X=4).
P(B wng)=P(X=3)+P(X=4)
=4C3(0.55)3(10.55)43+4C4(0.55)4(10.55)44
{4}C3(0.55)3(0.45)1+4C4(0.55)4(0.45)0
=(4×0.166375×0.45)+(1×0.0915×1)
=0.299475+0.0915
=0.390975
Thus, if Team A won the first game the probability that team B will win the series is 0.390975.

Do you have a similar question?

Recalculate according to your conditions!

New Questions in High school probability

Ask your question.
Get an expert answer.

Let our experts help you. Answer in as fast as 15 minutes.

Didn't find what you were looking for?