probability

This problem is based on sets.

The formula for 2 elements (A and B) of sets,

P(AuB)=P(A)+P(B)-P(AnB)

70=52+P(R)-38

P(R)=56

Hi Bubbly Rathi,

These are set theory questions. Please check your other question in which the trainer - learner - dancer has been discussed. The relationship between union, intersection and the individual sets has been provided there also.

Here goes ...

n(A union B) = n (A) + n (B) - n(A intersection B)

Note that, if there are 3 items,

n (A union B union C) =

n(A) + n(B) + n(C)
-n(A intersection B) - n(B intersection C) - n(C intersection A)
+ n(A intersection B intersection C)

Please pm me in case you would like to elaborate.

Hope this helps. Thanks !

The formula for 2 elements of sets is,

P(AuB)=P(A)+P(B)-P(AnB)

The formula for 3 elements of sets is,

P(AuBuC)=P(A)+P(B)+P(C)-P(AnB)-P(BnC)-P(CnA)+P(AnBnC)

4GMAT_Mumbai wrote:Hi Bubbly Rathi,

These are set theory questions. Please check your other question in which the trainer - learner - dancer has been discussed. The relationship between union, intersection and the individual sets has been provided there also.

Here goes ...

n(A union B) = n (A) + n (B) - n(A intersection B)

Note that, if there are 3 items,

n (A union B union C) =

n(A) + n(B) + n(C)
-n(A intersection B) - n(B intersection C) - n(C intersection A)
+ n(A intersection B intersection C)

Please pm me in case you would like to elaborate.

Hope this helps. Thanks !

dai ennoda post leh comment panna

This is first post in BTG I am seeing the comments in TAMIL:)

OA?

bubblyrathi,

As stuart pointed this is not a GMAT question.

Please post the question from the relevant source.