In a group of 400 people, 250 can speak Hindi and 200 can speak English. How many people can speak both Hindi and English?
∴ 60 = 40 + n(Y) - 10
n(Y) = 60-40+10 = 30
Hence, the number of elements in set Y = 30.
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?