1I think both the statements are correct and it is (a)... I don't understand why this isn't a well framed question ....
62Even i said to Krishna that i wud go for "A"
Btw this was a narayana question. and even the sir said. it could be both. (Not that we should give too much weight to his opinion!)
Why i said that this is not a well framed question is bcos the reason is not explained well enuf.
i mean that u need to have a margin where u say that this reason explains the assertion enuf...
See the correct reason for the above in my eyes is Independence of A and B! Or even if someone said Venn Diagram kind of stuff!
1
varun
·2008-11-22 03:20:49
If the probability of an event A is 0.4 and that of B is 0.3,then the probability of neither A nor B occuring depends upon the fact that A and B ,are mutually exclusive or not
If they are mutually exclusive, then the prob of them not occurring simultaneously will be 1-P(A)-P(B)..
If they can occur simultaneously, then 1-P(A)-P(B)+P(A∩B) ..
So, I concluded that it was correct reason ..
Edit: I meant, if they are not simultaneous, P(A∩B) = 0. So it depends on P(A∩B) = 0 which depends on whether they are mutually exclusive or not ..
62
Lokesh Verma
·2008-11-22 03:24:51
suppose that P(A∩B)=0 for a non exclusive case
Like universal set is [0,1] on the real line
A=[0,0.4]
B=[0.4,0.7]
Then A and B are not exclusive.. but still
P(A∩B) = 0
62
Lokesh Verma
·2008-11-22 03:26:02
That is the point varun..
P(A∩B) = 0 does not imply
that (A∩B) is empty set.. my example above!
1
varun
·2008-11-22 03:48:16
Hmm... so it depends on whether they are mutually exclusive or not .. but not only on that factor right ?
If they are mutually exclusive, P(A∩B) = 0 .. but if they are not, it may/mayn't be 0.
62
Lokesh Verma
·2008-11-22 03:51:37
yes varun...
But suddenly i have started to think that the assertion itself is wrong.. what say? :D
1
varun
·2008-11-22 03:55:33
Lol that was what I first thought after seeing your example !!
I think it will be more apt if we say that it depends on whether P(A∩B) = 0 or not... :D
62
Lokesh Verma
·2008-11-22 04:00:01
So i think we can converge on the thing that
(C) is the correct answer because the assertion itself is wrong!!