Hazeem repeatedly throws two ordinary fair 6-sided dice at the same time. On each occasion, the score is the sum of the two numbers that she obtains.

(a) Find the probability that it takes exactly 5 throws of the two dice for Hazeem to obtain a score of 8 or more.

(b) Find the probability that it takes no more than 4 throws of the two dice for Hazeem to obtain a score of 8 or more.