Which day you born in?
There are SEVEN day in the week, There are FOUR blood types in ABO, There are 24 hours in a day... But I will show about The days in a week with MATH.
Your birthday is on ---day! Am I right? "Hey! how do you know? " I know, that was a common math trick. But I should not tell you how to. That was just a part in the quiz. Want more? Play the quiz!