In a survey of 60 people, it was found that 25 people read newspaper H, 26 read newspaper T, 26 read newspaper I, 9 read both H and I, 11 read both H and T, 8 read both T and I, 3 read all three newspapers. Find:
the numbers of people who read at least one of the newspapers.
Total number of People n(P) = 60.
n(H) =25.
n(T) = 26.
n(I) = 26.
n (H ∩ I) = 9
n (H ∩ T) = 11
n (T ∩ I) = 8
n (H ∩T ∩ I) = 3
The people who read at least one newspaper would be n(H or I or T) = n(H∪I∪T)
We know,
n(H∪I∪T) = n(H)+n(I)+n(T) – n (H ∩ I)– n (H ∩ T)– n (T ∩ I)+ n (H ∩T ∩ I)
n(H∪I∪T) = 25+26+26–9–11–8+3
n(H∪I∪T) = 52.
There are 52 people who read at least one newspaper.