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Name: Answers
Score: 0 / 8 (0%)
[10 subjective questions not graded]
Worksheet: Odds
Multiple Choice
Identify the letter of the choice that best completes the statement or answers the question.
1. If the odds in favour of snow tomorrow are 4:7, what is the probability of snow tomorrow?
a.
b.
c.
d.
ANSWER: C
NOTES:
REF:
Knowledge & Understanding
2. If the odds of the Maple Leafs winning the Stanley Cup are 7:11, what is probability that they will
win the Stanley Cup?
a. 63.6%
b. 36.4%
c. 22.2%
d. 38.9%
ANSWER: D
NOTES:
REF:
Knowledge & Understanding
3. If you were to toss three coins, what are the odds against them all landing heads up?
a. 1:8
b. 8:1
c. 7:8
d. 7:1
ANSWER: D
NOTES:
REF:
Knowledge & Understanding
4. If the odds in favour of event A are 2:3, what is the value of P(A¢)?
a.
b.
c.
d.
ANSWER: A
NOTES:
REF:
Knowledge & Understanding
5. What are the odds in favour of randomly selecting a black face card from a standard deck of
cards?
a. 3:13
b. 3:26
c. 3:10
d. 3:23
f ile: / / / P: / M s. Sediako/ M DM 4U/ odds. ht m ?st udent _nam e=Answer s&M C% 3A1=+&M C% 3A2=+&M C% 3A3=…
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ANSWER: D
NOTES:
REF:
Knowledge & Understanding
6. The odds in favour of a runner winning a race in dry weather are 5 to 3. The same runner’s odds
in favour of winning on a humid day are 7 to 4. Which of the following statements is false?
a. The runner has a 62.5% chance of winning in dry weather.
b. The runner has a better chance of winning in humid weather.
c. The runner has a better chance of winning in dry weather.
d. The runner has a 36.4% chance of losing in humid weather.
ANSWER: C
NOTES:
REF:
Applications
7. What are the odds against randomly picking a green apple from a fruit bowl containing seven
green apples and four red ones?
a. 7:4
b. 4:11
c. 7:11
d. 4:7
ANSWER: D
NOTES:
REF:
Knowledge & Understanding
8. What is the probability of randomly selecting a blue sock from an unorganized sock drawer if the
odds in favour of not picking a blue sock are 3 to 7?
a.
b.
c.
d.
ANSWER: D
NOTES:
REF:
Knowledge & Understanding
Short Answer
9. What are the odds in favour of July 1st being a Tuesday?
RESPONSE:
ANSWER: 1:6
NOTES:
REF:
Applications
10. The probability of Jim hitting the bull’s-eye on a dart board is 0.04. What are the odds in favour
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of Jim not hitting the bull’s-eye?
RESPONSE:
ANSWER: 24:1
NOTES:
REF:
Applications
11. If the odds against the Blue Jays winning this year’s World Series are 20:1, what is the probability
that the Blue Jays will win this series?
RESPONSE:
ANSWER:
NOTES:
REF:
or about 0.048
Applications
12. What are the odds in favour of a total greater than 9 in a given roll of two standard dice?
RESPONSE:
ANSWER: 1:5
NOTES:
REF:
Applications
13. If the odds are 9:1 against the next car you see being red, what proportion of cars in your area are
red?
RESPONSE:
ANSWER: 10%
NOTES:
REF:
Applications
Problem
14. Describe how to calculate the odds against an event happening when you know the probability of
the event occurring. Use a numerical example to illustrate your explanation.
RESPONSE:
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ANSWER:
Answers may vary. Students should make the key point that the odds against the
event happening are given by the ratio
. For example, if the probability of the
event occurring is , then the probability of it not happening is , and the odds
against the event are
NOTES:
REF:
, or 1:2.
Communication
15. The Royals’ coach stated that “the odds in favour of us winning the next game are 5:7, the odds of
tying the next game are 1:3, and the odds of losing the next game are 2:3.” Can the coach’s
predictions be correct? Justify your answer.
RESPONSE:
ANSWER: The coach is incorrect.
If the odds are 5:7 in favour of winning, then
If the odds are 1:3 in favour of tying, then
If the odds are 2:3 in favour of losing, then
These three probabilities add to
.
.
.
, which is impossible, since probabilities of all
possible outcomes is always 1.
NOTES:
REF:
Communication, Thinking/Inquiry/Problem Solving
16. Explain how you would calculate the tomorrow’s “probability of precipitation” if the odds against
precipitation tomorrow are 4:1.
RESPONSE:
ANSWER:
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If the odds against having rain are 4:1, then the probability of not having rain is .
Therefore, the probability of precipitation must be
NOTES:
REF:
, or 20%.
Applications, Communication
17. Explain why odds of 4 to 5 in favour of an event occurring have a different meaning than the same
event having a probability of .
RESPONSE:
ANSWER:
The odds of 4 to 5 mean that the event has a probability of . Thus, odds of 4 to
5 are quite different from a probability of .
NOTES:
REF:
Communication
18. If you were to toss four coins, what are the odds in favour of at least two landing heads up?
RESPONSE:
ANSWER:
P(tossing at least two
heads)
1 - P(no heads) - P(one head)
1-
-
Therefore, the odds in favour of tossing at least two heads are 11:5.
NOTES:
REF:
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Applications
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