Download Amber Green Probability Revision

Amber Green Probability Revision - Mr. Widmer
Question 1
Simon's mathematics class has ten boys and ten girls. A student is selected at random.
a) The change of selecting a girl is greater than 0.5.
b) The chance of selecting a boy is 0.5.
c) Selecting a boy is more likely than selecting a girl.
Question 2
The probability of getting green using this spinner is:
a. 0
b. 0.25
c. 0.5
d. 1
Question 3
The pointer of this spinner is on green.
If it is spun, the probability of it stopping on green is:
a) less than 50%
b) greater than 50%
c) exactly 50%
Question 4
In the refrigerator there are twelve strawberry yoghurts, seven passionfruit yoghurts and one mango yoghurt.
Shivani reaches into the refrigerator and takes a yoghurt out at random. The probability that the yoghurt is
mango flavoured is:
%
Question 5
A probability is said to be
.
This could be the probability of randomly selecting:
a) 3 from the sample space {3, 3, 3, 3, 3, 3, 3, 3, 3}
b) 4 from the sample space {1, 2, 3, 4, 5, 6, 7, 8, 9}
c) 2 from the sample space {1, 8, 2, 3, 2, 7, 4, 5, 9}
d) 7 from the sample space {4, 3, 2, 1, 5, 4, 6, 8, 9}
Question 6
Brown bears attempt to catch salmon. During the day, 20% of the attempts are successful. During the night,
36% of attempts are successful.
A bear tries to catch 40 fish during the day and makes 50 attempts at night.
Use probability to estimate the number of fish the bear caught.
Question 7
Students were asked whether they liked cake F or G or both.
How many students were surveyed?
Question 8
Water samples were taken from different ponds and were tested for the presence of bacteria A and bacteria B.
How many ponds had both bacteria A and bacteria B?
Question 9
What is the probability of randomly selecting an element from set C?
P(C) = 9
Question 10
Different ponds were tested for the presence of bacteria A and bacteria B.
If a pond is selected at random, what is the probability that it contains at least one of the bacteria?
Question 11
Which of these best describes the shaded region of the diagram?
a.
b.
c.
d.
elements not in Q
elements not in Q or R
elements not in Q and R
elements not in R but not in Q
Question 12
From the group of animals shown in the diagram, there is a 30% probability of selecting an animal with claws
and no fur.
How many of these animals have claws but not fur?