Download 5 - Royton and Crompton School

1.
Coloured cubes
There are some cubes in a bag. The cubes are either red (R) or black (B).
The teacher says:
If you take a cube at random out of the bag,
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the probability that it will be red is
5
(a)
What is the probability that the cube will be black?
...............................
1 mark
(b)
A pupil takes one cube out of the bag. It is red.
What is the smallest number of black cubes there could be in the bag?
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1 mark
(c)
Then the pupil takes another cube out of the bag.
It is also red.
From this new information, what is the smallest number of black cubes
there could be in the bag?
...............................
1 mark
(d)
A different bag has blue (B), green (G) and yellow (Y) cubes in it. There is
at least one of each of the three colours.
The teacher says:
If you take a cube at random out of the bag,
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the probability that it will be green is
5
Royton and Crompton School
1
There are 20 cubes in the bag.
What is the greatest number of yellow cubes there could be in the bag?
Show your working.
............................
2 marks
2.
Probability
(a)
A bag has 20 cubes in it. 6 of the cubes are green.
You take one cube out of the bag at random.
Which values below show the probability that you take out a cube that is green?
Circle the correct four values.
6
14
30%
0.6
3/10
6%
3/5
6/20
0.03
0.3
6/10
60%
6
26
2 marks
(b)
A box has 20 counters in it. 11 of the counters are red.
You take one counter out of the box at random.
What is the probability that the counter you take out is not red?
Write your answer as a fraction.
1 mark
Now write your answer as a percentage.
1 mark
Royton and Crompton School
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3.
Alun has these two spinners.
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8
1
12
2
3
Alun spins both spinners and then adds up the numbers to get a total.
He starts to make a list of all the possible totals.
Complete Alun’s list.
Totals
5
2 marks
4.
Counters
I have two bags of counters.
Bag A contains
12 red counters and
A
18 yellow counters.
Bag B contains
10 red counters and
B
16 yellow counters.
I am going to take one counter at random from either bag A or bag B
I want to get a red counter.
Which bag should 1 choose?
Show working to explain your answer.
2 marks
Royton and Crompton School
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5.
Playing a game
Anita is going to play a game.
The probability that she will win the game is 0.7
Is she more likely to win the game or lose the game?
Tick ( ) Win or Lose.
Win
Lose
Explain how you know.
1 mark
Royton and Crompton School
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