Q8. 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?
n(french) = 50
n(spanish) = 20
n(speak both french and spanish) = 10
n(speak at least one of these two languages) = n(french) + n(spanish) - n(speak both french and spanish)
n(speak at least one of these two languages) = 50 + 20 - 10
n(speak at least one of these two languages) = 70 -10
n(speak at least one of these two languages) = 60
Hence,60 people speak at least one of these two languages.