In a certain population group, 59% of the people have characteristics X and 66% have characteristics Y. If every person in the group has at lest one of the of the two characteristics, then what percent of the people have both X and Y?

প্রশ্ন : In a certain population group, 59% of the people have characteristics X and 66% have characteristics Y. If every person in the group has at lest one of the of the two characteristics, then what percent of the people have both X and Y?
সমাধান:
N (X) = 59%
N (Y)= 66%
N (X ∪ Y) = 100%

অতএব,
N (X ∪ Y) = N (X) + N (Y) - N (X ∩ Y)
বা, N (X ∩ Y) = N (X) + N (Y) - N (X ∪ Y)
= 59% + 66% - 100%
= 125% - 100%
= 25%