Probability question where an object is chosen randomly out of two objects

tantrik

New member
Joined
Sep 18, 2016
Messages
14
Dear friends,

I am stuck at the following probability problem. Will appreciate your help.

Two opera singers, Mario and Clarissa both performon the same night, in separate recitals. The independent probabilities that two newspapers X and Y publish reviews of their recitals are given below:

Probability of review in newspaper X
====================================
Mario's recital - 1/2
Clarissa's recital - 2/3

Probability of review in newspaper Y
================================ ====
Mario's recital - 1/4
Clarissa's recital - 2/5

Mario buys oneof the newspapers at random. What is the probability that it has reviewed "both" recitals?


I did this way: P(reviewed both recitals) = P(buys paper X)*P(X reviews Mario)*P(X reviews Clarissa) = (1/2)*(1/2)*(2/3)= 1/6


But 1/6 is not the correct answer. Let me know where I am wrong andwhy.

Thanks in advance.
 
Dear friends,

I am stuck at the following probability problem. Will appreciate your help.

Two opera singers, Mario and Clarissa both performon the same night, in separate recitals. The independent probabilities that two newspapers X and Y publish reviews of their recitals are given below:

Probability of review in newspaper X
====================================
Mario's recital - 1/2
Clarissa's recital - 2/3

Probability of review in newspaper Y
================================ ====
Mario's recital - 1/4
Clarissa's recital - 2/5

Mario buys oneof the newspapers at random. What is the probability that it has reviewed "both" recitals?


I did this way: P(reviewed both recitals) = P(buys paper X)*P(X reviews Mario)*P(X reviews Clarissa) = (1/2)*(1/2)*(2/3)= 1/6


But 1/6 is not the correct answer. Let me know where I am wrong andwhy.

Thanks in advance.
I'm not sure there is an answer to the problem. Suppose Mario (M) and Clarissa (C) gave separate recitals 6 different times and look at the results for newspaper X; M is reviewed 3 times and C is reviewed 4 times. HOWEVER, we don't know the overlap for either paper. It could have been
M 3 times, C 4 times, both 3 times, and neither 2 times or
M 3 times, C 4 times, both 2 times, and neither 1 time or
M 3 times, C 4 times, both 1 times, and neither 0 times
Similarly with newspaper Y.
 
Top