IIT JEE 2006 Paper : MATHEMATICS Section III - Comprehension Passage 2
Each question below has only one correct answer.
In the IIT-JEE, you will be awarded 5 marks for each correct answer and −2 for each incorrect answer.
You will be awarded 0 marks for not attempting a question.
You are given n boxes numbered 1 to n. The ith box contains i white and (n + 1 − i)red balls. Let Ei and W respectively denote the event of selecting ith box at random and the event that the ball drawn from the selected box is white.