My Math Forum Formulation of a Question - Probability

 Probability and Statistics Basic Probability and Statistics Math Forum

December 13th, 2012, 03:02 PM   #1
Newbie

Joined: Dec 2012

Posts: 1
Thanks: 0

Formulation of a Question - Probability

Hello, I'm new in this forum
I'm not a native English speaker, so I apologize for any mistakes in advance.

This problem was in my Mathematics test:
Quote:
 A ship has disappeared in the ocean. We admit that the situation has been caused by any of the following equiprobable causes: sinking sequestration destruction by storm To each case, the probability of the rescuing team manages to rescue all the crewmembers alive is, respectively, 4/5, 3/5 and 7/10 [1st question - Calculate the probability of all crewmembers with life being saved.] 2nd question - We now know that 14 crewmembers were saved and that the cause of the disappearance was not the storm. After all, how many crewmembers were in the aforesaid ship?
My teacher says the answer for the 2nd question is 30.
I say the question makes absolutely no sense, as all we know are the odds (conditioned for each cause) for all of the crewmembers to survive. 14/30 would be the propotion between the number of rescues with all people saved and the total number of rescues.
I tried to explain my view to her, but she says she doesn't understand my problem with this question... Am I crazy or is she the one who seriously needs holidays?

December 14th, 2012, 01:35 PM   #2
Global Moderator

Joined: May 2007

Posts: 6,684
Thanks: 658

Re: Formulation of a Question - Probability

Quote:
 To each case, the probability of the rescuing team manages to rescue all the crewmembers alive is, respectively, 4/5, 3/5 and 7/10
The teacher seems to interpret that statement to mean the probability that a given person is rescued is the number stated.

As stated the problem is insoluble.

 Thread Tools Display Modes Linear Mode

 Similar Threads Thread Thread Starter Forum Replies Last Post mghg13 Calculus 2 February 12th, 2013 01:28 PM lalitp Algebra 1 December 12th, 2012 01:27 AM momo Number Theory 1 April 11th, 2009 10:49 PM

 Contact - Home - Forums - Cryptocurrency Forum - Top