maths grade 9 ujian sekoah

7/31/2019 Maths Grade 9 Ujian Sekoah

1/10


2/10

Working:

Answer:

......................................................................

(Total 4 marks)

3. A survey is carried out to find the waiting times for 100 customers at a supermarket.

waiting time

(seconds)

number of

customers

030 5

30 60 15

60 90 33

90 120 21

120150 11

150180 7

180210 5

210240 3

(a) Calculate an estimate for the mean of the waiting times, by using an appropriate

approximation to represent each interval. (2)

(b) Construct a cumulative frequency table for these data.(1)

(c) Use the cumulative frequency table to draw, on graph paper, a cumulative frequency

graph, using a scale of 1 cm per 20 seconds waiting time for the horizontal axis and 1 cm

per 10 customers for the vertical axis.(4)

(d) Use the cumulative frequency graph to find estimates for the median and the lower

and upper quartiles.(3)

(Total 10 marks)


3/10

3


4/10


5/10

(a) Use the cumulative frequency curve to complete the frequency table below.

Mark (x) 0 x < 20 20 x < 40 40 x < 60 60 x < 80 80 x < 100

Number of

students22

20

(b) Forty percent of the students fail. Find the pass mark.

Working:

Answer:

(b) ..(Total 6 marks)

5. A box contains 35 red discs and 5 black discs. A disc is selected at random and its colour noted.

The disc is then replaced in the box.

(a) In eight such selections, what is the probability that a black disc is selected

(i) exactly once?(3)

(ii) at least once?(3)

(b) The process of selecting and replacing is carried out 400 times.

What is the expected number of black discs that would be drawn?(2)

(Total 8 marks)

5


6/10

6. Two ordinary, 6-sided dice are rolled and the total score is noted.

(a) Complete the tree diagram by entering probabilities and listing outcomes.

. . . . . . .

. . . . . . .

. . . . . . .

. . . . . . .

. . . . . . .

. . . . . . .

. . . . . . .

. . . . . . .

. . . . . . .

. . . . . . .

6

6

6

n o t 6

n o t 6

n o t 6

O u t c

(b) Find the probability of getting one or more sixes.

Working:

Answer:

(b) ...............................................................

(Total 4 marks)


7/10

7. In a survey of 200 people, 90 of whom were female, it was found that 60 people were

unemployed, including 20 males.

(a) Using this information, complete the table below.

Males Females Totals

Unemployed

Employed

Totals 200

(b) If a person is selected at random from this group of 200, find the probability that this

person is

(i) an unemployed female;

(ii) a male, given that the person is employed.

Working:

Answers:

(b) (i) ..........................................................

(ii) ..........................................................

(Total 4 marks)

7


8/10

8. (a) Factorize x2

3x 10.

(b) Solve the equation x2

3x 10 = 0.

Working:

Answers:

(a) ..................................................................

(b) ..................................................................

(Total 4 marks)

9. Find the sum of the arithmetic series

17 + 27 + 37 +...+ 417.

Working:

Answer:

.........................................................................

(Total 4 marks)


9/10

10. An arithmetic series has five terms. The first term is 2 and the last term is 32. Find the sum of

the series.

Working:

Answer:

......................................................................

(Total 4 marks)

11. Find the sum of the infinite geometric series

...81

16

27

8

9

4

3

2++

Working:

Answer:

......................................................................

(Total 4 marks)

9


10/10

12. Each day a runner trains for a 10 km race. On the first day she runs 1000 m, and then increases

the distance by 250 m on each subsequent day.

(a) On which day does she run a distance of 10 km in training?

(b) What is the total distance she will have run in training by the end of that day? Give your

answer exactly.

Working:

Answers:

(a) ..................................................................

(b) ..................................................................

(Total 4 marks)

maths grade 9 ujian sekoah

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