There are two gentlemen A and B who are running for mayor in a certain city. It
ID: 3369473 • Letter: T
Question
There are two gentlemen A and B who are running for mayor in a certain city. It is known that the chance of being elected by A will be 0.6, and that of B will be elected at 0.4 If A is elected, the city will have a chance to build a large gymnasium with a probability of 0.8. When B Jun is elected, the probability of the city building a large gymnasium is 0.3. A. What is the probability that the city will build a large gymnasium? B. This city will build a large stadium. What is the chance of being elected mayor by B?Explanation / Answer
a)P(city will build a large gymnasium)=P(A elected and large gymnasium+B elected and large gymnasium)
=0.6*0.8+0.4*0.3=0.6
b)
P(B elected|large gymnasium))=P(B elected and large gymnasium)/P(large gymnasium)
=0.4*0.3/0.60=0.2