this is generic enough what limitation r u talking abt

Hi there,

I'm also not quite clear on what you question is. This page has a nice list of set theory formulas with a Venn diagram so you can visualize it. It should help clarify: https://gmat-maths.blocked/2008/05/ ... mulas.html

Thanks Vivian for providing the link
According to it ,

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

By True # of items, I mean actual no. of item in a set.
If there are three sets, then what is the formula for calculating actual no. of items
I found below formula from one of the posts on BTG.
But I think the below formula and the one I found on the link given by you are not same.

True # of items = (total # in group 1) + (total # in group 2) + (total # in group 3) - (# in only groups 1/2) - (# in only groups 1/3) - (# in only groups 2/3) - 2(# in all 3 groups) + (# in no groups)

Please help

Here are some formulas that can be useful while dealing with 3 sets

Total number of people/Number of people in at least one set:
AuBuC = A + B + C - AnB - AnC - BnC + AnBnC

Number of people in exactly one set:
A + B + C - 2*AnB - 2*AnC - 2*BnC + 3*AnBnC

Number of people in exactly two of the sets:
AnB + AnC+ BnC - 3*AnBnC

Number of people in two or three sets:
AnB + AnC + BnC - 2*AnBnC

Number of people in exactly three of the sets =
AnBnC