Page 161 - Mathematics Coursebook

End of unit review

End of unit review

1 Choose the correct word or phrase from the box to describe each outcome.
a A coin will come up heads each time when it is spun three times. likely certain
b The number shown when a dice is thrown will be less than 8. unlikely even chance
c It will rain in the next month. very likely impossible
d The population of the world will be less in 20 years’ time than it is now. very unlikely
2 Mark these probabilities on a probability scale.
2
1
A: Passing an exam: . B: Failing the exam: . 0 1
3 3
C: A good harvest: 95%. D: Jo’s horse winning the race: 0.2.
3 Omar lays out ten cards, numbered from 1 to 10, face down. He takes one Write your answers
card at random. What is the probability that the number on his card is: as decimals.
a 7 b less than 4 c an even number d a multiple of 3 e not the 10?

4 A large jar of sweets has equal numbers of red, yellow, green and orange sweets and no
other colours.
Anil takes out a sweet without looking. What is the probability that it is:
a yellow b either red or green c not orange?

5 What is wrong with Zalika’s argument?

If I throw two dice and add the scores together I can get any total from 2 to 12.
That’s 11 different numbers, so the probability of getting a total of 3 is 1 .
11

Tamsin throws a single dice.
6 Tamsin throws a single dice.
a Find the probability of each outcome.
T: She scores 3. M: She scores more than 3. L: She scores less than 3. N: She does not score 3.
b State whether each of these statements is true or false.
i M and L are mutually exclusive events. ii T and N are mutually exclusive events.
iii M and N are mutually exclusive events.
7 Aisha chooses a whole number from 1 to 20, at random. Here are three possible outcomes.
F: a multiple of 4 S: a multiple of 7 P: a prime number
a Find the probability of each of the outcomes F, S and P.
b Explain why F and P are mutually exclusive outcomes but S and P are not.

8 Tanesha throws two dice and adds the scores together.
Here are her results after 80 throws.
Total less than 5 from 5 to 10 more than 10

Frequency 16 56 8
a Find the experimental probability that the total is:
i less than 5 ii more than 10 iii 5 or more.
b In 20 more throws, two scores are less than 5. Find the new experimental probability of
‘less than 5’.

160 16 Probability