題組內容

11. (30%) A study show that in an exan the time required to come up with the correct answer for each question is a cont tinuous memoryless random variable with the ex expected value equal to the difficulty level of the question. The time to answer each question is independent of each other.

(a) (6%) The first and second questions both have dificulty level 2. Denote T as the random variable representing the total I time I required to come up with the correct answers for both questions. Write down the PDF of T.