Download Name Date Unit Test: Unit 11 Probability 1. A jar is filled with 48

Name
Date
Unit Test: Unit 11 Probability
1.
A jar is filled with 48 yellow jelly beans, 43 red jelly beans, 52 orange jelly beans, and 57 green
jelly beans. One jelly bean is picked at random.
a) What are the possible outcomes?
b) What is the probability of picking each colour of jelly bean?
2.
A regular tetrahedron is labelled 1 to 4. A number cube is labelled 1 to 6.
The tetrahedron and cube are rolled.
a) Record the numbers on the faces that do not show.
Are you more likely to get the answer 8 if you add these numbers or multiply them?
Explain your answer.
_________________________________________________________
_________________________________________________________
_________________________________________________________
b) Make up your own problem about the tetrahedron and cube. Solve the problem.
Show your work.
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3.
Each of two spinners has congruent sectors. Spinner A has 4 sectors coloured red, green, yellow,
and black. Spinner B has 3 sectors coloured red, green, and purple.
a) The pointer on each spinner is spun. Use a tree diagram to list the possible outcomes.
b) What is the probability that the colours are different? Explain.
c) What is the probability that only one colour is red? Explain.
d) What is the probability that no colour is red? Explain.
e) What is the probability that no colour is orange? Explain.
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4. a) In her 85 times at bat, Jillian got 55 hits. What is her batting average?
b) A home cleaning service solicits new business by telephone. On one day,
500 telephone calls were made. They produced 111 new customers.
What is the relative frequency of getting a customer over the phone? Explain.
c) A quality controller at a battery manufacturing company tested 360 batteries from the
production line. She found that 19 were defective.
A box contains 5000 batteries.
How many might you expect not to be defective?
Show two different ways to solve this problem.
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Name
Master 11.12
Date
Sample Answers
Unit Test – Master 11.11
1. a)
b)
2. a)
b)
3. a)
Yellow, red, orange, green
The total number of jelly beans is 200:
48 + 43 + 52 + 57 = 200.
The probability of picking a:
48
6

yellow jelly bean is
=
or 0.24
200 25
43

red jelly bean is
or about 0.22
200
52 13

orange jelly bean is
=
or 0.26
200 50
57

green jelly bean is
or 0.28
200
Students can draw addition and multiplication tables.
There are 2 ways to get 8 if you multiply:
2  4 and 4  2.
There are 3 ways to get 8 if you add: 6 + 2,
5 + 3, 4 + 4.
So, you are more likely to get 8 if you add the
numbers that show.
Sample problem: You can divide the number on the
cube by the number on the tetrahedron, or you can
subtract the number on the tetrahedron from the
number on the cube. With which operation are you
more likely to get the answer 2?
Solution: There are 3 ways to get the answer 2 if
you divide: 2  1, 4  2, 6  3.
There are 4 ways to get the answer 2 if you
subtract: 3 – 1, 4 – 2, 5 – 3, 6 – 4. So, you are more
likely to get 2 if you subtract.
b)
c)
d)
e)
4. a)
b)
c)
10 5
= ; 10 out of 12 outcomes have
12 6
2 different colours.
5
; 5 out of 12 outcomes have only 1 red sector.
12
6 1
= ; 6 out of 12 outcomes have no red sectors.
12 2
1; there are no orange sectors, so all outcomes
never have orange.
55
=˙ 0.647, or approximately 65%
85
111
=˙ 0.222, or approximately 22%
500
Solution Method 1: 19 are defective, so
360 – 19 = 341 are not defective. So, the
probability of not being defective is
341
=˙ 0.947.
360
Multiply the probability by the number of
341
batteries.
 5000 =˙ 4736
360
So, approximately 4736 batteries should not
be defective.
Solution Method 2: The probability of being
19
defective is
=˙ 0.053.
360
Find out how many batteries will be defective.
Multiply the probability of being defective by 5000.
19
 5000 =˙ 263.9 or approximately
360
264 batteries will be defective. The number of
non-defective batteries will be
5000 – 264 = 4736.
So, approximately 4736 batteries should not
be defective.
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