1 Which of these properly reflects the Law of Or A PE1 or E2

1 Which of these properly reflects the Law of Or?

A) P(E1 or E2) = [P(E1) + P(E2)]/ [P(E1) + P(E2)]

B) P(E1 or E2) = P(E1) - P(E2)

C) P(E1 or E2) = P(E1) / P(E2)

D) P(E1 or E2) = P(E1) + P(E2)

2 Which of these events is not mutually exclusive?

A) the chance that you will get a heads or tails when you flip a coin once.

B) the chance that you will only study for the test alone or with a friend.

C) the chance that you will meet your friends for pizza or at a chinese restaurant for dinner today at 6.

D) the chance that you will answer the ringing phone or take a walk.

3 If a prize can be found under only one of the three shells, and the possible prizes are a quarter (8%), a bottle cap (80%) and a hermit crab (12%), what are the chances of lifting a shell and finding the crab?

A) 12 %

B) 45 %

C) 4 % .

D) 4%

4 Which of these pairs are not independent of each other?

A) The probability that your favorite color is green and your favorite sport is baseball.

B) The probability that it will rain and the probability that you will have to mop muddy floors.

C) The probability that you will go to a party on friday night and that your hair is brown.

D) The probability that when you roll a dice, you will first roll a 6 and then a 2.

5 Which Law would you use to answer the following question: What is the chance of flipping a coin and getting four heads in a row? (NOTE: H1 = heads on the first roll, H2 = heads on the second roll, etc.)

A) P(4 heads in a row) = P(H1) x P(H2) x P(H3) x P(H4)

B) P(4 heads in a row) = P(H1) + P(H2) + P(H3) + P(H4)

6 Suppose in flies, red eyes are dominant over brown eyes. If for this trait, a homozygous dominant fly is mated with a heterozygous fly, what is the probability that the fly will have brown eyes?

A) 50 %

B) 25%

C) 0%

D) 100%

7 If in humans, brown eyes are dominant over green eyes, and two heterozygous parents have three children, what is the probability that all of the kids will have green eyes?

A) 33%

B) 75%

C) 1.5%

D) 3%

8. If the probability that a plant will release seeds is 75%, the probability that a given seed will germinate is 50%, and the probability that a germinating plant will be eaten by a deer before it matures is 20%, what is the probability that a parent will see its progeny survive to adulthood?

A) 2%

B) 30%

C) 14.5%

D) 7.5%

9 If in humans, brown eyes are dominant over green eyes, and two heterozygous parents have three children, what is the probability that at least one of the kids will have brown eyes?

A) 14.1%

B) 18.8%

C) 46.8%

D) 98.5%

10 You roll two dice (each die has six sides). What is the probability that you won\'t roll a 1 or a 6 on either die?

A) 44.4%

B) 69.4%

C) 66.7%

D) 11.1%

Solution

1. The law of OR is

D) P(E1 or E2) = P(E1) + P(E2)

2. B) the chance that you will only study for the test alone or with a friend.

3. A) 12 %

4. B) The probability that it will rain and the probability that you will have to mop muddy floors.

5. A) P(4 heads in a row) = P(H1) x P(H2) x P(H3) x P(H4)

6. B) 25 %

7. C) 1.5 %

8. B) 30% (0.75*0.5*0.80 = 0.30 =30%)

9. D) 98.5%

10. C) 66.7% (4/6 = 0.667 = 66.7%)