When coin 1 is flipped, it lands on heads with probability
3
5
; when coin 2 is flipped it lands on heads with probability
9
10
.
(a)
If coin 1 is flipped 8 times, find the probability that it
lands on heads at least 6 times.
(b)
If one of the coins is randomly selected and flipped 10 times,
what is the probability that it lands on heads exactly 7
times?
(c)
In part (b), given that the first of these 10 flips lands on
tails, find the conditional probability that exactly 7 of the 10
flips land on heads.