Question

In a committee, if 50 people speak French, 20 people speak Spanish, 10 people speak both the languages, then how many people speak at least one of the two languages?

(a) 10

(b) 20

(c) 50

(d) 60

This question was posed to me in semester exam.

This is a very interesting question from Practical Problems on Union and Intersection of Two Sets topic in section Sets of Mathematics – Class 11

Answer 1

The correct answer is (d) 60

Best explanation: We know, n (F∪S) = n (F) + n (S) – n(F∩S)

Given, n (F)=50, n (S)=20, n (F∩S) = 10

n (F∪S) = 50 + 20 – 10 = 60.

60 people speak at least one of the two languages.