Year 10 5.2 Probability

An event has the probability of occurring equal to 0.

What word can you use to describe this probability?

• Certain

• Impossible

• Likely

• Unlikely

Two cards are selected without replacement from cards labelled 1 to 3.

What is the sample space?

• {1, 2, 3}

• {1, 1, 2, 2, 3, 3}

• {11, 12, 13, 21, 22, 23, 31, 32, 33}

• {12, 13, 21, 23, 31, 32}

A bag contains black, grey and white balls.

The probability of selecting a black ball is 0.3 and a grey ball is 0.6.

What is the probability of selecting a white ball?

• 0.1

• 0.36

• 0.63

• 0.9

A letter is chosen at random from the word 'NEWCASTLE'. What is the probability the letter will be E?

• $\frac{1}{9}$

• $\frac{2}{9}$

• $\frac{1}{3}$

• $\frac{2}{3}$

The frequency of selecting a red card from a deck was recorded to be 6. If 20 cards were selected overall, what is the relative frequency of selecting a red card?

• 14%

• 26%

• 30%

• 70%

The arrow is spun. 

What is the probability that the arrow will stop in a section containing a number greater than 4?

• $\frac{2}{5}$

• $\frac{2}{3}$

• $\frac{1}{3}$

• $\frac{1}{2}$

Which of the following events would be LEAST likely to occur?

• Tossing a fair coin and obtaining a head

• Rolling a standard six-sided die and obtaining a 3

• Randomly selecting the letter 'G' from the 26 letters of the alphabet

• Winning first prize in a raffle of 100 tickets in which you have 4 tickets

Each time she throws a dart, the probability that Mary hits the dartboard is  $\frac{2}{7}$ 

She throws two darts, one after the other.

What is the probability that she hits the dartboard with both darts?

•  $\frac{1}{21}$  

•  $\frac{4}{49}$  

•  $\frac{2}{7}$  

•  $\frac{4}{7}$  

Jaz has 2 bags of apples.

Bag A contains 4 red apples and 3 green apples.

Bag B contains 3 red apples and 1 green apple.

Which tree diagram could be used to determine the probability that Jaz chooses a red apple?

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Which of the following could be the probability of an event occurring?

• 1

• $\frac{6}{5}$

• 1.27

• 145%