1.

In a family of 10 members, 7 of them like tea or coffee, 4 of them like tea and 5 of them like coffee. How many of them like both tea and coffee?(a) 1(b) 2(c) 7(d) 9I had been asked this question in unit test.My doubt is from Practical Problems on Union and Intersection of Two Sets in section Sets of Mathematics – Class 11

Answer»

The correct answer is (b) 2

The best I can explain: We know, N (T ∪ C) = n (T) + n (C) – n (T ∩ C)

GIVEN, n (T ∪ C) = 7, n(T)=4, n(C)=5

7 = 4 + 5 – n (T ∩ C)

n (T ∩ C) = 2.

Hence, 2 members like both tea and coffee.


Discussion

No Comment Found

Related InterviewSolutions