In a room of 36 people. 20 players play chase while 28 players play poker. How many players play both?

Correct Answer: 12
আমরা জানি, Total = n(A) + n(B) - both + none ⇒ 36 = 20 + 28 - both + 0 ⇒ 36 = 48 - both ⇒ both = 48 - 36 ⇒ both = 12