In: Statistics and Probability
When coin 1 is flipped, it lands on heads with probability 3 /5 ; when coin 2 is flipped it lands on heads with probability 7 /10 .
(a) If coin 1 is flipped 9 times, find the probability that it lands on heads at least 7 times.
(b) If one of the coins is randomly selected and flipped 8 times, what is the probability that it lands on heads exactly 5 times?
(c) In part (b), given that the first of these 8 flips lands on heads, find the conditional probability that exactly 5 of the 8 flips land on heads.