In a group of 25 women, 17 have nose studs, 8 have ear rings and 5 have neither. How many of these have both nose studs and ear rings?
In a group of 25 women, 17 have nose studs, 8 have ear rings and 5 have neither. How many of these have both nose studs and ear rings?
1). 0
2). 2
3). 5
4). 7
1 answers
This question is related to sets. Let us denote the set of women wearing nose studs as N and the set of women wearing ear rings as E.
Now, since there are 3 women not wearing either nose studs or earing,
hence, number of women wearing nose studs or ear rings = 25 – 5 = 20
⇒ N ? E = 20
⇒ N + E – (N ? E) = 20
⇒ 17 + 8 – (N ? E) = 20
⇒ 25 – (N ? E) = 20
⇒ N ? E = 25 – 20 = 5
∴ Number of women wearing nose studs and ear rings is equal to 5.Other Questions
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