A certain bowler can bowl a strike 70% of the time. If the bowls are independent, what's

Question:

A certain bowler can bowl a strike 70% of the time. If the bowls are independent, what's the probability that she
a) Goes three consecutive frames without a strike?
b) Makes her first strike in the third frame?
c) Has at least one strike in the first three frames?
d) Bowls a perfect game (12 consecutive strikes)?