Question

In a committee, 50 people speak French, 20 speak Spanish and 10 speak both Spanish and French. How many speak at least one of these two languages?

Answer 1

Let F is the set of people who speak French and S who speak Spanish
Here, `n(F)=50,n(S)=20 and n(F capS)=10`
Now, `n(F cup S)=n(F)+n(S)-n(F capS)`
`= 50 +20 - 10 = 60`
Therefore, the number of people who speak at least one of these two languages French and Spanish = 60.