A die is biased so that, when it is rolled, the probability of obtaining a score of 6 is. The probabilities of obtaining each of the other five scores 1, 2, 3, 4, 5 are all equal. Calculate the probability of obtaining a score of five with this biased die.

(a) The biased die and an unbiased die are now rolled together. Calculate the probability that the total score is 11 or more.

(b) The two dice are rolled again. Given that the total score is 11 or more, calculate the probability that the score on the biased die is 6. (C)