申論題

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.

(e) (6%) The fifth question has diffculty level 7 while the sixth question has difficulty level 8. 'Due to time constraint, you have time to write only one question. What is the probability that the time to finish the fifth question is shorter than the time to finish the sixth question?