Question

In a city of 1000 population, all people read newspaper. 600 people read Hindustan Times and 700 people read Times of India. How many people read both newspaper?

(a) 100

(b) 300

(c) 1000

(d) 1300

This question was posed to me during an interview for a job.

I want to ask this question from Practical Problems on Union and Intersection of Two Sets in chapter Sets of Mathematics – Class 11

Answer 1

The correct choice is (b) 300

Best explanation: Since all people read newspaper so, n (T ∪ H) = 1000.

n(H) = 600 and n(T) = 700.

n (T ∪ H) = n (T) + n (H) – n (T ∩ H)

1000 = 700 + 600 – n (T ∩ H)

n (T ∩ H) = 1300-1000 = 300.