2 probability questions... please explain how you arrived at your answer if possible--thanks!

(1) A fair die is rolled 8 times. What is the probability of getting:

a) 1 on each of the eight rolls?

b) 6 exactly twice in the eight rolls?

c) 6 at least once in the eight rolls?

(2) In a car race, there are 6 Chevrolets, 4 Fords, and 2 Pontiacs. In how many ways can the 12 cars finish if we consider only the make of the cars?