1someone flips 12 biased coins once the coins are weighted such that the probability of a head
with any coin is 70.
a what is the probability of getting exactly 9 heads?
b what is the probability of getting at least 9 heads?
c. what is the probability of getting 4 tails?
2. at a local race track, each race has 5 horses. assume that the horses are equally matched in
each race such that every horse has an equally likely chance of winning. if you went to this
particular track and bet on 12 races, what is the probability that you would pick the winner in
а 6 races
b. less than 6 races
c. either 3 races or more than 7 races
d between 4 and 8 races (inclusive)
e. at least 3 races
3. a multiple choice exam has 4 answer choices (a, b,c, d). there are 20 questions on the exam.
assuming you guessed on every question what is the probability that you would get:
a. 10 correct
b. at least 5 correct
c. more than 15 correct
d. 12 incorrect