Page 436 - Math Smart - 7

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Describe the likelihood of the following events.

a) The sun will rise in the west.
b) Tomorrow will be Monday if today is Sunday.
c) You have a bag with 9 red balls and 1 white ball.
i) You draw a white ball. ii) You draw a red ball. ii) You draw a green ball.

There is a hot drink vending machine in an office. A survey was
Drink Frequency^.^
conducted to find the probabilities of an employee choosing
each type of drink. Each employee could only choose one drink. coffee 0.5
Draw a decimal probability scale. Mark the probability of each 1
tea
4
drink being chosen on the probability scale.
a) Which drink is most likely to be chosen? hot chocolate 20%
b) Which drink is least likely to be chosen? cappuccino 0.05
c) Show this data on a probability tree diagram.

5 dominoes are placed face down. Sarah randomly
chooses one domino. What is the probability that
Sarah will pick up a domino with
•
•
a) a blank on it?
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b) five dots on it?
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c) seven dots in total?
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This spinner is used in a game.
The spinner is spun once. The arrow indicates the score achieved.
a) Use a probability tree diagram to show all the possible scores.
b) What is the most likely score?
c) What is the probability of getting a score of 1 ?

A company manufactures batteries. They want to know how
long the batteries can last. They tested a sample of 100 batteries.
The results are in the table below.

Battery life (h) Frequency
Less than 10 h 4
From 10 h to less than 20 h 46

From 20 h to less than 30 h 39
30 h or more 11

Estimate the probability of a battery chosen at random lasting
a) less than 10 hours.
b) more than 10 hours and less than 30 hours.
c) more than 30 hours.