Q1) In conditional probability, P(wear rain coat | it rains) means the probability of wearing rain coat ________________.*

multiplied by the probability of raining

divided by the probability of it raining

no matter whether it rains or not

if it rains

Q2) Suppose P(wear rain coat | it rains) = 1/2, and P(wear rain coat | it does not rain) = 1/3. Today, the probability of raining is 1/4. What is the (overall) probability of someone wearing a rain coat today?*

1/8

1/4

3/8

1/2

none of the above

Q3) Cont from Q2). A person would only complain if either (s)he wears raincoat but it does not rain, or does not wear raincoat but it rains. What is the (overall) probability that a person complains today?*

1/8

1/4

3/8

1/2

none of the above

Q4) There are 5 red pills and 4 blue pills in a jar. Two pills are randomly picked. What is the probability that both pills are red?*

2/9

10/9

5/18

20/27

25/81

Q5) Cont. from Q4). What is the probability that two pills are picked, and have are different colours?*

4/9

5/9

2/3

7/9

none of the above

Q1) At a high school, some students walk home, while others take bus. (Assume there is no third way.) A random student is interviewed. What is the probability that the student walks home?*

1/2

less than 1/2

more than 1/2

could be any of the above

Q2) A student did not prepare for a Kahoot game, so she randomly guessed answer. If she has guessed the first 6 questions wrong, what is her chance of guessing the 7th answer correctly?*

1/4

less than 1/4

more than 1/4

could be any of the above

Q3) A teacher is known to distribute the answers of multiple choice quite evenly among A, B, C, and D. In one particular test, there are 7 multiple choice questions. The answer of the first two questions are both A. What is the probability that the next answer is still A?*

1/4

less than 1/4

more than 1/4

could be any of the above

Q4) The more times a (regular) coin is flipped...*

the more likely the head shows close to half of the time

the less likely the head shows close to half of the time

the probability of head increase over 1/2

the probability of head decrease under 1/2

Q5) A student took this exact quiz, and concluded that the probability of your math teacher picking "C" (third option) as the correct answer is less than 1/4. What is your opinion?*

P(C) = exactly 1/4

P(C) < 1/4

P(C) > 1/4

need to look at more quizzes