Re: Expected cutoff for dse ??

Posted by Ameya on Jul 05, 2013; 4:05am
URL: http://discussion-forum.276.s1.nabble.com/Expected-cutoff-for-dse-tp7583160p7583219.html

there are two types of questions..the one you mention does not have order. it says one is daughter so the possibilities are DD, DS, SD out of which the probability is 1/3
However in the letter question,
you work at a newspaper company, you recieve two letters everyday. the postman has a ladies first policy, provided there is a letter from a female. the postman has delivered the first letter for the day and it is from a female. what is the probability that the second is also from a female.
The difference in this question is order is given. we know that the 'first' letter is from a female. the second, therefore, can be from a male or a female. only two possibilities. hence, 1/2