NO.PZ2023091601000007
问题如下：
A risk analyst at an investment management firm interested in
blockchain technology is monitoring the performance of a stablecoin project in
an Asian country. The analyst finds that the project is regulated by a central
monetary authority that will soon decide whether to distribute the stablecoins
for public use, and notes that the following events could occur:
• Event A: The monetary authority
distributes the stablecoins
• Event B: Businesses in the country
accept the stablecoins as payment
The analyst also
estimates the following probabilities: P(A): 70% , P(B): 40% ,P(B|A): 20%
What
is the probability of either event A or event B occurring?
选项：
A.0.29
B.0.60
C.0.84
D.0.96
解释：
D is correct. Our
goal is to find P(B U A), which is given by P(B U A) = P(A)+P(B)-P(BՈA). To
calculate this, we first denote the following events:
Let P(A) =
probability that the central monetary authority distributes the stablecoins to
the public for use = 70%
P(B) = probability
of businesses accepting stablecoins as payment = 40%
P(B|A) =
probability of businesses accepting stablecoins as payment given that the
central monetary authority distributes the stablecoins to the public for use =
20%.
From the
following, we can obtain P(BՈA) = P(B|A)*P(A) = 0.20*0.70=0.14.
We want to find
P(A U B) or P(B U A).
P(B U A) =
P(A)+P(B)-P(BՈA) = 0.40+0.70-0.14 = 0.96 or 96%.
A is incorrect.
This is P(B|A)/P(A).
B is incorrect.
This is P(B|A)+P(B).
C is incorrect.
This is P(BՈA)+P(A).
a或b发生的概率，可以理解为a发生b不发生+b发生a不发生的概率和么，即不包括a和b不能同时发生？
