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

Answer:

Let F be the set of people in the committee who speak French, and S be the set of people in the committee who speak Spanish.

∴n(F)=50,n(S)=20,n(S∩F)=10

We know that:

n(S∪F)=n(S)+n(F)−n(S∩F)

=20+50−10

=70−10=60

Thus, 60 people in the committee speak at least one of the two languages.