Out of 600 mobile owners investigated, 500 owned Nokia hand set and 180 owned Tata hand set; 30 owned both Nokia and Tata hand sets. Is this data correct?

Asked by Topperlearning User | 17th Apr, 2014, 01:18: PM

Expert Answer:

Let U denote the universal set consisting of all mobile owners, N denote the set of all owners of Nokia hand set and T denote the set of all owners of Tata hand- set.

n(U) = 600, n(N) = 500, n(T) = 180, n(N  T) = 30.
So, we have
n (N T)   = n(N) + n(T) – n(N  T)
                   = 500 + 180 – 30 = 650

Also, N  T is a subset of U.

      But  n (N  T)  n(U)

       650  600, which is impossible.

       Given data is incorrect.

Answered by  | 17th Apr, 2014, 03:18: PM