The Student Room Group

S1 question, please help me understand.

this always happens to me. i get all the other parts of the question, but when it comes to the last part, i DONT even get it.
ok the question is:

the members of a wine tasting club are married couples. for any married couple, the prob of the husband being retired is 0.7
the prob of a wife being retired is 0.4
given that the wife is retired, the probability that the husband is retired is 0.8.
for a randomly chosen married couple who are members of the club, find the prob that:

a) both are retired
b) only one of them is retired
c) neither of them is retired
two married couples are chosen at random
d) find the prob that only one of the two husbands and only one of the two wives is retired.


PLS PLS PLS HELP ME UNDERSTAND THE LAST PART!!!!!!!
Original post by papajani1234
this always happens to me. i get all the other parts of the question, but when it comes to the last part, i DONT even get it.
ok the question is:

the members of a wine tasting club are married couples. for any married couple, the prob of the husband being retired is 0.7
the prob of a wife being retired is 0.4
given that the wife is retired, the probability that the husband is retired is 0.8.
for a randomly chosen married couple who are members of the club, find the prob that:

a) both are retired
b) only one of them is retired
c) neither of them is retired
two married couples are chosen at random
d) find the prob that only one of the two husbands and only one of the two wives is retired.


PLS PLS PLS HELP ME UNDERSTAND THE LAST PART!!!!!!!


http://www.thestudentroom.co.uk/forumdisplay.php?f=38

The maths forum may be a better place to post these questions :h:

I would try to help but I am puzzled by the solutions :s-smilie: it doesn't quite make sense to me either.
Reply 2
Original post by papajani1234
this always happens to me. i get all the other parts of the question, but when it comes to the last part, i DONT even get it.
ok the question is:

the members of a wine tasting club are married couples. for any married couple, the prob of the husband being retired is 0.7
the prob of a wife being retired is 0.4
given that the wife is retired, the probability that the husband is retired is 0.8.
for a randomly chosen married couple who are members of the club, find the prob that:

a) both are retired
b) only one of them is retired
c) neither of them is retired
two married couples are chosen at random
d) find the prob that only one of the two husbands and only one of the two wives is retired.


PLS PLS PLS HELP ME UNDERSTAND THE LAST PART!!!!!!!


So a is 0.32
B is 0.3992
C is 0.5704
D is 0.6184 i think

Not sure if its right let me know if it is
Reply 3
Original post by metrize
So a is 0.32
B is 0.3992
C is 0.5704
D is 0.6184 i think

Not sure if its right let me know if it is


I'm afraid to say that all of them are incorrect, this is the thing with stats, if you get one part wrong - THE WHOLE thing's wrong !!! :bawling::eek4:

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