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ANGLICAN HIGH SCHOOL
Preliminary Examination 2010 Secondary Four
NAME
Class / Index Number 4 /
MATHEMATICS 4016 / 01
Paper 1 17 August 2010
2 hours
Candidates answer on the Question Paper.
READ THESE INSTRUCTIONS FIRST Write in dark blue or black pen in the spaces provided on the Question Paper. Do not use staples, paper clips, highlighters, glue or correction fluid. Answer all questions. If working is needed for any question it must be shown with the answer. Omission of essential working will result in loss of marks. Calculators should be used where appropriate. If the degree of accuracy is not specified in the question, and if the answer is not exact, give the answer to three significant figures. Give answers in degrees to one decimal place. For π, use either your calculator value or 3.142, unless the question requires the answer in terms of π. At the end of the examination, fasten all your work securely together. The number of marks is given in brackets [ ] at the end of each question or part question. The total of the marks for this paper is 80.
For Examiner’s Use
This Question Paper consists of 14 printed pages.
Write down the model of your calculator used:
Signature of Parent/Guardian & Date
Name of Parent/Guardian 80
Page | 2 AHS Prelim 2010 Sec 4 Mathematics Paper 1
Mathematical Formulae
Compound interest
Total amount = 𝑃 1 +𝑟
100 𝑛
Mensuration
Curved surface area of a cone = πrl
Surface area of a sphere = 4πr2
Volume of a cone = 1
3𝜋𝑟2
Volume of a sphere = 4
3𝜋𝑟3
Area of triangle ABC = 1
2 ab sinC
Arc length = 𝑟𝜃, where 𝜃 is in radians
Sector area = 1
2𝑟2𝜃, where 𝜃 is in radians
Trigonometry
𝑎
sin𝐴 =
𝑏
𝑠𝑖𝑛𝐵 =
𝑐
𝑠𝑖𝑛𝐶
𝑎2 = 𝑏2 + 𝑐2 − 2𝑏𝑐 cos𝐴
Statistics
Mean =
𝑓𝑥
𝑓
Standard deviation = 𝑓𝑥2
𝑓−
𝑓𝑥
𝑓
2
[Turn over
Answer all the questions.
1 Expressed as the product of prime factors,
360 = 2
3 3
2 5 and
84 = 22 3 7
Use these results to find
(a) the higher common factor of 360 and 84.
(b) the smallest positive integer k, such that 360k is a cube number.
Answer (a) [1]
(b) k = [1]
2 (a) Write the following numbers in order of size, starting with the largest.
648.2 ,13
112 ,648.2 ,684.2
(b) Calculate the simple interest when $ 12500 is invested for 9 months at 0.2 % per
annum.
Answer (a) [1]
(b) $ [1]
Page | 4 AHS Prelim 2010 Sec 4 Mathematics Paper 1
3 Given that 94 p and 16 q , find
(a) the greatest possible value of p q ,
(b) the smallest possible value of 𝑝 + 𝑞
𝑞
(c) the smallest possible value of )( 22 qp
Answer (a) [1]
(b) [1]
(c) [1]
4 The rate of exchange between Japanese yen (¥) and Singapore dollars ($) was
¥ 64.1 = $ 1.
(a) Joanne bought a handbag for ¥ 23 000 in Japan. How much is the cost of the
handbag in SGD?
(b) A similar handbag costs $ 414.40 in Singapore. What is the difference in the
price between the two countries in SGD?
[Correct your answers to the nearest dollars]
Answer (a) $ [1]
(b) $ [1]
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5 (a) Write the following numbers correct to four significant figures,
(i) 385.047
(ii) 0.00192287.
Answer (a) (i) [1]
(ii) [1]
(b) Express 9
16 as a percentage.
Answer (b) % [1]
6
(a)
(i) Calculate
2.51− 1.23−7.836 3
20.7 ×96.45+18.01 , showing all the figures on your
calculator display.
(ii) Give your answer correct to 3 decimal places.
Answer (a) (i) [1]
(ii) [1]
(b) Evaluate (2.77 10 –3
) (5.911 10 –7
) ,give your answer in standard form.
Answer (b) [1]
Page | 6 AHS Prelim 2010 Sec 4 Mathematics Paper 1
7 Factorise the following expressions completely
(a) ac + 2bc – 3 ad – 6 bd
(b) 2x2 – 32
Answer (a) [1]
(b) [1]
8 A map is drawn to a scale of 1: 250 000. Find
(a) the actual distance, in kilometres, of a highway which is 28 cm in length on the
map.
(b) the area, in cm2, of a garden on the map which has an actual area of 37.5 km
2.
Answer (a) km [1]
(b) cm2
[1]
[Turn over
9 Liquid is poured into the empty container, as shown in the diagram, at a constant rate.
It filled the container up to a height of d1 in 5 minutes and takes another 5 minutes to
fill up to d2.
On the axes in the answer space, sketch the graph showing the depth (d) of the liquid
varies with time (t).
[2]
Answer
10 The line 𝑥
2−
𝑦
3 = 6 cuts the y–axis at the point P. Find
(a) The coordinates of the point P,
(b) The gradient of the line.
Answer (a) (……. , …….) [1]
(b) [1]
Liquid in
d2
d1
d1
d2
Depth of
liquid (d)
Time (minutes)
0 5 10
Page | 8 AHS Prelim 2010 Sec 4 Mathematics Paper 1
11 In the diagram, points A, B and C are on level ground. 86ABC . C is due north
of A and B is in the direction 050 from A. Find
(a) the bearing of B from C.
(b) Find the area of ∆ 𝐴𝐵𝐶 when AC = 5 m and AB = 4 m.
Answer (a) o
[1]
(b) m2
[2]
12 Given that 13
25
3
2
x
xyy
(a) Calculate the value of y when x = −1
8
(b) Express y in terms of x.
Answer (a) y = [2]
(b) [2]
N
B
A
C
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13 The temperature at 0500 is – 12o C
The temperature at 1330 is 24o C
(a) Find the difference between the two temperatures.
(b) Assuming that the temperature rises at a steady rate, find
(i) the temperature at 0800, correct your answer to one decimal place.
(ii) the time when the temperature is 0o C
Answer (a) o
[1]
(b) (i) o
[2]
(ii) [1]
14 If = {pupils of a school}, F = {female pupils} and S = {Singaporeans}.
(a) Draw a Venn diagram to represent the above information.
[2]
(b) Shade the area that represents male Singaporean pupils.
Answer (a) & (b)
(c) Express each of the following statements in set notation.
(i) Female pupils who are Singaporeans.
(ii) Male pupils who are non Singaporeans.
Answer (c) (i) [1]
(ii) [1]
Page | 10 AHS Prelim 2010 Sec 4 Mathematics Paper 1
15 The scale drawing in the answer space below shows a circle with diameter AB and Q is
a point on the circumference of the circle.
(a) Construct the bisector of angle QAB.
(b) Construct a right–angled triangle ABC such that C lie on the bisector of angle
QAB and ABC = 90o. Label the point C.
(c) Measure and write down the size of angle ACB.
Answer
[2]
Answer (c) ACB = o
[1]
A
B
Q
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16 In the diagram, AFDB and CGEB are straight lines. BDE and DEF are two isosceles
triangles and FDE = 36o.
(a) Find FEC.
Answer (a) FEC = o
[2]
(b) By construction, determine the maximum number of isosceles triangles that can
be added in the given diagram such that the vertices of the triangle(s) are on the
two given lines.
Answer (b) [2]
(c) Justify your answer in (b) with reason. [1]
Answer
C
A
36
F
E
B
D
Page | 12 AHS Prelim 2010 Sec 4 Mathematics Paper 1
17 It is known that a certain parabola cuts the x–axis at –3 and 4.
(a) Write down the equations of two quadratic curves that fit this description, and
sketch them on the axes in the answer space.
Answer (a) [1]
[1]
[3]
(b) Write down the equation(s) of the line of symmetry of the curves that you have
drawn.
(b) [1]
x
y
O
[Turn over
18 The points A, B, C and D lie on a circle. A smaller circle, centre C, passes through
points B, E and F and AFC is straight line. ADC = 79o and BAC = 21
o.
Giving your reasons, find
(a) angle CBA,
(b) angle FCB,
(c) angle CFE, if CF is parallel to EB.
Answer (a) CBA = ° [1]
(b) FCB = ° [1]
(c) CFE = ° [2]
79
21
F
C
A
D
B
E
Page | 14 AHS Prelim 2010 Sec 4 Mathematics Paper 1
19 ABCD is a parallelogram. 𝐴𝐵 = 𝒂, 𝐵𝐶 = 𝒃, 3BX = 2XC and AE = 3
5𝐴𝑋.
(a) Given that 𝒂 = 25 and 𝒃 =
50 , find
`
(i) 𝐴𝑋
(ii) 𝐵𝐸
(iii) 𝐸𝐷
Answer (a) (i) units [2]
(ii) [1]
(iii) [1]
(iv) Hence, show that B, E and D are collinear.
Answer
[1]
(b) Write down, as a fraction in its simplest form, the value of
𝐴𝑟𝑒𝑎 𝑜𝑓 ∆𝐴𝐵𝐸
𝐴𝑟𝑒𝑎 𝑜𝑓 𝑝𝑎𝑟𝑎𝑙𝑙𝑒𝑙𝑜𝑔𝑟𝑎𝑚 𝐴𝐵𝐶𝐷
(b) [2]
A
B C
D
X
E a
b
[Turn over
20 The cumulative frequency shows the time in minutes taken by a group of 32
competitors to complete a Sudoku puzzle.
Using the graph, to estimate
(a) the median,
(b) the interquartile range,
(c) the number of competitors that took 14 minutes or less to complete the game,
(d) the percentage of competitors that took 19.5 minutes or more to complete the
game.
Answer (a) min [1]
(b) min [2]
(c) [1]
(d) % [2]
Cumulative Frequency Curve of Time Taken To Solve Sudoko Puzzle
Number of Competitors
Time (min)
4
0
8
12
16
20
24
28
32
8 10 12 14 16 18 20 22 24 26
Page | 16 AHS Prelim 2010 Sec 4 Mathematics Paper 1
21 The first four terms in a sequence of numbers, p1, p2, p3, p4, …, are given below.
p1 = 12 + 2
2 + 2
2 = 9
p2 = 22 + 3
2 + 6
2 = 49
p3 = 32 + 4
2 + 12
2 = 169
p4 = 42 + 5
2 + 20
2 = 441
(a) Write down an expression for p5 and show that p5 = 961.
Answer (a)
[1]
(b) Write down an expression for p6 and evaluate it.
Answer (b)
[1]
(c) Show that pn = n4 + 2n
3 + 3n
2 + 2n + 1.
Answer (c)
[3]
(d) Given that p10 = 102 + 11
2 + r
2 = k, express k as a perfect square in terms of r.
Answer (d) k = [1]
(e) Given that pw = w2 + (w + 1)
2 + r
2 = 5257
2 , find the value of r and of w.
Answer (e) r = [1]
w = [1]
END OF PAPER
[Turn over
1 (a) HCF of 360 and 84 = 4 3 = 12
(b) k = 3 52 = 75
2 (a) 2.8466 2.84646 2.84615 2.846846
Answer :
648.2
684.2
648.2 13
112
(b) simple interest = 12500 × 9
12 × 0.002
= $ 18.75
3 (a) the greatest possible value of p q = (–4) (–1) = 4
(b) the smallest possible value of 𝑝 + 𝑞
𝑞
= the smallest possible value of ( 𝑝
𝑞+ 1) =
9
−1 + 1 = –8
(c) the smallest possible value of )( 22 qp = 0 2 + (–1)
2 = 1
4 (a) The cost of the handbag in $ = 23 000 64.1 = $ 358.81 $ 359
(b) The difference in the price between the two countries in $
= 414.40 – 358.81 = $ 55.59 $ 56
5 (a) (i) 0.002177359
(ii) 0.002
(b) – 17134913.82 – 17130000
= – 1.713 × 107
6 (a) 1 : 250 000 = 1 cm : 250 000 cm
= 1 cm : 2.5 km
= (1 28) cm : (2.5 28) km
= 28 cm : 70 km
Actual Distance = 70 km
(b) (1cm)2
: (2.5 km)
2 = 1 cm
2 : 6.25 km
2
= (1 37.5
6.25) cm
2 : (6.25
37.5
6.25) km
2
= 6 cm2
: 37.5 km2
map area = 37.5 km2
7 (a) When x = 0, y = –18, P is (0, –18)
(b) y = 3𝑥
2 – 18, gradient = 3/2
8 (a) ac + 2bc – 3 ad – 6 bd = c (a + 2b) – 3d (a + 2b)
= (c – 3d) (a + 2b)
(b) 2x2 – 32 = 2(x
2 – 16) = 2(x – 4)(x + 4)
Page | 18 AHS Prelim 2010 Sec 4 Mathematics Paper 1
9
10 (a) Bearing of B from C = 86 + 50 = 136°
(b) Area = 1
2× 5 × 4 × 𝑠𝑖𝑛50° = 7.6604 ≈ 7.66 𝑚2
11 (a) Difference = 24o C – (–12
o C) = 36
o C
(b) (i) the temperature at 0800 = – 12o + 36𝑜 ×
(8 – 5)
(13.5 − 5)
= 0.705 o C
0.7 o C
(ii) the time when the temperature is 0o C
= 0500 + (13.5 – 5) ×12𝑜
36𝑜
= 0500 + 17
6
= 0500 + 170
60
= 0500 + 2 hr 50 min
= 0750
12 (a) & (b)
(c)(i) 𝐹 ∪ 𝑆
(ii) 𝐹 ∪ 𝑆 ′ 𝑜𝑟 𝐹′ ∩ 𝑆′ 13
(a) sub x = −1
8 into
13
25
3
2
x
xyy
1)
8
1(3
)8
1(25
3
2
yy
4
315
4
11
8
11 yy
d1
d1
Depth of liquid
(d cm)
Time (minutes)
0
d2
2 4 6 8 10 12
E
SF
[Turn over
C
A
B
Q
2
8
131y
131
16y
(b)
13
25
3
2
x
xyy
)25(3)13)(2( xyxy
xyxxy 61526)13(
215)13( yxy
2)163( xy
xor
xy
316
2
163
2
14 (a) & (b)
(c) The point of intersection is the centre of the given circle.
(d) ACB = 90o
15 (a) DBE = 36o/2 = 18
o
DFE = 36o
FEC = DBE + DFE (ext of BEF)
= 18o + 36
o = 54
o
(b)
Construct lines FG and GH
2 more isosceles triangles can be drawn
(c) HFG = (18 + 54)o = 72
o
FHG = 72o
HGC = 18o + 72
o = 90
o
No further triangles can be drawn.
A
C
36
H
G
F
E
B
D
Page | 20 AHS Prelim 2010 Sec 4 Mathematics Paper 1
16 (a) y = (x + 3)(x – 4) (There are other possible answers)
and y = – (x + 3)(x – 4)
(b) x = 0.5
17 (a) CBA = 180o – CDA (s in opp segment)
= 180o – 79
o
= 101o
(b) FCB = 180o – BAC – CBA (s sum of ABC)
= (180 – 21 – 79)o
= 80o
(c) CFE = FEB (alt. s, CF // EB)
= ½ FCB ( at centre = 2at circumference)
= 40o
18 (a) (i) 𝐴𝑋 = 𝐴𝐵 + 𝐵𝑋
= 24
+ 1
3
60
= 44
𝐴𝑋 = 42 + 42 = 32 ≈ 5.66 𝑢𝑛𝑖𝑡𝑠
(ii) 𝐵𝐸 = 𝐵𝐴 + 𝐴𝐸
= −2−4
+ 3
4
44 =
1−1
(iii) 𝐸𝐷 = 𝐸𝐴 + 𝐴𝐷
= −3
4
44 +
60
= 3−3
= 3 1−1
Since 𝐵𝐸 𝑎𝑛𝑑 𝐸𝐷 have common vector 1−1
from same point E, therefore B, E and D are
collinear.
x
y
O
y = – (x + 3)(x – 4)
–3 4
– 12.25 y = (x + 3)(x – 4)
12.25
–
12
12
[Turn over
(b)
𝐴𝑟𝑒𝑎 𝑜𝑓 ∆𝐴𝐵𝐸
𝐴𝑟𝑒𝑎 𝑜𝑓 ∆𝐴𝐵𝐷 =
12𝐴𝐵×𝐵𝐸𝑠𝑖𝑛∠𝐴𝐵𝐷
12𝐴𝐵×𝐵𝐷𝑠𝑖𝑛∠𝐴𝐵𝐷
= 𝐵𝐸
𝐵𝐷 =
14𝐵𝐷
𝐵𝐷 =
1
4
𝐴𝑟𝑒𝑎 𝑜𝑓 ∆𝐴𝐵𝐸
𝐴𝑟𝑒𝑎 𝑜𝑓 𝑝𝑎𝑟𝑎𝑙𝑙𝑒𝑙𝑜𝑔𝑟𝑎𝑚 𝐴𝐵𝐶𝐷=
𝐴𝑟𝑒𝑎 𝑜𝑓 ∆𝐴𝐵𝐸
2×𝐴𝑟𝑒𝑎 𝑜𝑓 ∆𝐴𝐵𝐷 =
1
8
19 (a)(i) Median =13.5 min
(ii) Interquartile range = 16 – 12 = 4 min
(iii) No of competitors = 18
(iv) Percentage = 4
32× 100 = 12.5%
(b) The lower quartile or median or upper quartile for the 2008 competition is higher than
the 2009 competition. This shows that the quality of the competitors in the 2009 batch
seems to be better than the 2008 batch.
The inter-quartile range for the 2008 competition is wider than the 2009 competition.
This shows that the 2009 competitors are relatively more competitive.
20 (a) p5 = 52 + 6
2 + 30
2 = 25 + 36 + 900 = 961
(b) k = (s + 1)2
(c) r = 5256
w (w + 1) = 5256 = 72 × 73
w = 72
(d) pn = n2 + (n + 1)
2 + [n(n +1)]
2
= n2 + n
2 + 2n + 1 + n
2(n + 1)
2
= 2n2 + 2n + 1 + n
2(n
2 + 2n + 1)
= 2n2 + 2n + 1 + n
4 + 2n
3 + n
2
= n4 + 2n
3 + 3n
2 + 2n + 1.
Anglican High School Preliminary Examinations 2010
Name ( ) Class 4 ________
Thursday 19 August 2010 2 hours 30 minutes
Additional Materials: 8 pieces of writing paper and 1 piece of graph paper. INSTRUCTIONS TO CANDIDATES
Answer all questions. Write your answers on the writing papers provided. Omission of essential working will result in loss of marks. Calculators should be used where appropriate. If the degree of accuracy is not specified in the question, and if the answer is not exact, give the answer to three significant figures. Give answers in degrees to one decimal place. For , use either your calculator value or 3.142, unless the question requires the answer in
terms of .
INFORMATION FOR CANDIDATES
The number of marks is given in brackets [ ] at the end of each question or part question. The total of the marks for this paper is 100.
Question 1 2 3 4 5 6 7 8 9 10 11
Marks
This question paper consists of 9 printed pages.
For Examiner’s Use
100
ANGLICAN HIGH SCHOOL
Preliminary Examination Secondary Four
MATHEMATICS 4016/02
Assessment noted by :
_____________________________ _____________________________ _____________________________
Name of Parent/Guardian Signature of Parent/Guardian Date
Anglican High School Preliminary Examinations 2010 Mathematics Paper 2
2
Mathematical Formulae
Compound Interest
Total amount =
nr
P
1001
Mensuration
Curved surface area of a cone = rl
Surface area of a sphere = 24 r
Volume of a cone = hr 2
3
1
Volume of a sphere = 3
3
4r
Area of triangle ABC = Cabsin2
1
Arc length = r , where is in radians
Sector area = 2
2
1r , where is in radians
Trigonometry
C
c
B
b
A
a
sinsinsin
Abccba cos2222
Statistics
Mean = f
fx
Standard deviation =
22
f
fx
f
fx
Anglican High School Preliminary Examinations 2010 Mathematics Paper 2
3
Answer all the questions.
1 (a) A train travelled a distance of 375 km in 5 hours from Station A to Station B. After
taking a break of 45 minutes, it travelled a further distance of 157.5 km at an average
speed of 90 km/h.
Calculate:
i) its average speed for the first part of the journey, [1]
ii) the time taken, in hours and minutes, for the second part of the journey, [1]
iii) its average speed for the whole journey. [3]
(b) Solve the equation
32−𝑥 = 1
35𝑥+13 [2]
(c) Express the following as a single fraction in its simplest form.
5 + 𝑦
25 − 𝑦2−
3
𝑦 − 5 [3]
2 (a) A soccer club has 150 members. X is the set of strikers. Y is the set of defenders.
The letters a, b and c in the Venn diagram represent the number of members in
each of the subsets of X and Y. The letter d represents the numbers of members
who are neither strikers nor defenders. Given that n(X) = 90 and n(Y) = 68, find
(i) the value of b if d = 0, [1]
(ii) the value of d if b = c, [1]
(iii) the largest possible number of members who are neither strikers nor
defenders. [1]
X
Y
a b
c
d
Anglican High School Preliminary Examinations 2010 Mathematics Paper 2
4
2 (b) The table below shows the number of pens own by each student in a class.
Number of pens 0 1 2 3 4 5
Number of students 1 3 x 7 5 2
(i) If the mode of the distribution is 3, find the range of values of x. [1]
(ii) If the median is 3, what is the largest value of x. [1]
(iii) If the mean is 2.9, find the value of x. [2]
3 (a)
The diagram shows the arcs AB and EF of a circle, centre O, with radius r cm.
BCX, OP and EDY are straight lines that are perpendicular to the line segment
AXPYF. CDYX is a rectangle with CX = 4 cm and AX =XY =YF = 5cm.
i) Show that r = 8.5 cm [1]
ii) Calculate the arc AB. [4]
(b) The cost price of a particular model of camera is $300. Shop A advertises its sale
as “usual price $450 now $360”. Shop B sells the same model of camera at $420
after a 25% discount.
Calculate
i) the discount given by shop A as a percentage, [2]
ii) the original marked price of the camera at shop B, [1]
iii) the profit gained by shop B as a percentage. [2]
B E
C D
A X P Y F
O
Anglican High School Preliminary Examinations 2010 Mathematics Paper 2
5
4 (a) It takes 3 hours and 10 min for 5 workers to paint a hall. Given that all the workers
work at the same rate, how long will 2 workers take to paint the same hall?
[Leave your answer in hours and minutes] [2]
(b) Mr Hai takes x minutes to carve a swan out of a block of ice and Mr Li takes 25
more minutes to carve an identical sculpture. If both of them work together, it only
takes 30 minutes to complete carving an identical sculpture.
i) Form an equation involving x, and show that it simplifies to
x2 – 35x – 750 = 0. [2]
ii) Determine the time taken by Mr Li to carve the sculpture on his own.
[3]
(c) i) Solve – 4 < 2x – 5 13 [2]
ii) Write down all the prime numbers which satisfy this condition. [1]
5 The diagram shows a solid in which ABCD, DCFE and ABFE are rectangles. G is the
foot of perpendicular from D to AE. Given that AB = 5 cm, AD = 8 cm, DE = 5.5 cm
and angle DAE is 25°.
Find,
(i) the length of DG, [1]
(ii) angle DCG, [2]
(iii) the length of AE, [4]
C
A
B F
D
E G
5 cm 8 cm 5.5 cm
25o
Anglican High School Preliminary Examinations 2010 Mathematics Paper 2
6
6 Two shops A and B sell the same brand of compact discs (CDs) and printing paper. Each
box of CDs is sold at $3.70 and $3.80 at Shop A and Shop B respectively. Each ream of
paper is sold at $6.80 and $6.50 at Shop A and Shop B respectively. The prices of the
items are represented by the matrix P,
𝑷 = 3.70 3.806.80 6.50
Andrew plans to buy 6 boxes of CDs and 2 reams of paper. Betty plans to buy 4 boxes of
CDs and 3 reams of paper. Charles plans to buy 5 boxes of CDs and 1 ream of paper.
(i) Represent the quantities of CDs and papers to be bought by the 3 persons as
a matrix Q. [1]
(ii) Evaluate the product, R = QP [2]
(iii) State what the elements of R represent. [1]
(iv) Evaluate T = (1 1 1) R. [1]
(v) State what the elements of T represent. [1]
(vi) If Andrew, Betty and Charles combine their purchase, which shop will give them a
better deal. [1]
7 A bowl of sweets contains 12 chocolate nuggets, 13 mints and 15 toffees. Mr Chan takes
two sweets at random and eats them.
(a) Draw a tree diagram to represent all the possible outcome. [3]
(b) Calculate the probability, as a fraction in its simplest form, that
i) a chocolate nugget and a mint was taken. [1]
ii) none of the two sweets chosen were toffees. [1]
(c) A third sweet was randomly taken from the bowl. Calculate the probability that the
first two sweets drawn were of the same type and the third was a chocolate nugget.
[2]
Anglican High School Preliminary Examinations 2010 Mathematics Paper 2
7
8. The diagram shows two regular octagons that meet at points A and B.
(a) Find the size of each interior angle of the octagons.
[1]
(b) Find PAQ.
[2]
(c) Show that
𝐴𝐵
𝐴𝐶 = 1.85, correct to 3 significant figures.
[3]
(d) Hence or otherwise, find the area of the smaller octagon if the area of the bigger
octagon is 36.2 cm2.
[3]
9. The diagram shows a circle, centre O and radius 3 cm.
An inscribed triangle ABC is
drawn with A and B on the
y-axis. AC is extended to
meet the x-axis at D and
OD meets BC at E.
(a) Prove that triangles BOE and DOA are similar.
[3]
(b) If OE = 1 cm,
(i) find OD,
(ii) show that AC = 3 10
5 cm,
(iii) hence find the exact length of DC.
[2]
[3]
[2]
y
xE
C
A
B
OD
Q
C
B
P
A
Anglican High School Preliminary Examinations 2010 Mathematics Paper 2
8
10
O, P , W and R are points on a horizontal plane. A vertical memorial tower, OT, is due
north of P. The angle of elevation of a man at P to the top of the tower is 15°. He walks a
distance of 200 metres to point W. Given that the bearing of W from P is 040° and the
bearing of O from W is 280°, calculate
i) ∠PWO, [2]
ii) OP, [2]
.
iii) the height of the tower OT, [2]
iv) the angle of depression of W from T. [2]
From W, the man walks 150 metres to a point R on a bearing of 𝜃° on the horizontal
plane. At R, the angle of elevation of the man to the top of the tower is 10°.
Calculate
v) angle OWR, [3]
vi) the value of 𝜃. [1]
N
N
R
T
O
P 150 m 200 m
15O
40O
280O
W
Anglican High School Preliminary Examinations 2010 Mathematics Paper 2
9
11. Answer the whole of this question on a sheet of graph paper.
The variables x and y are connected by the equation
𝑦 = 3 2𝑥 − 4.
Some corresponding values of x and y are given in the following table.
x –2 –1 0 1 2 3 4
y a –2.5 –1 2 8 20 44
(a) Find the value of a.
[1]
(b) Using a scale of 2 cm to 1 unit, draw a horizontal x–axis for –2 ≤ x ≤ 4.
Using a scale of 2 cm to 5 units, draw a vertical y–axis for –5 ≤ y ≤ 45.
On your axes, plot the points given in the table and join them with a smooth curve.
[3]
(c) Use your graph to find the solution of 2𝑥 = 9.
[2]
(d) By drawing a tangent, find the gradient of the curve at the point (3, 20).
[2]
(e) Use your graph to find the solutions of the equation 3 2𝑥 − 10𝑥 − 8 = 0.
[3]
END OF PAPER
Anglican High School Preliminary Examinations 2010 Mathematics Paper 2
11
AHS 2010 Prel EM P2 Answers
1ai) 75 km/h 1aii) 1 h 45 min 1aiii) 71 km/h 1b) –3 ½ 1c) 4/(5 – y)
2ai) 8 2aii) 26 2aiii) 60
2bi) 0 ≤ 𝑥 ≤ 6 2bii) 9 2biii) 2
3aii) 15.0 cm 3bi) 20% 3bii) $ 560
3biii) 40% 4a) 7 hrs 55 min 4bii) 1 hr 15 min
4ci) ½ < x 9 4cii) 2, 3, 5, 7 5i) 3.38 cm
5ii) 34.1o 5iii) 11.6 cm 6vi) Shop B
6i)
6 24 35 1
6ii)
35.80 35.8035.20 34.7025.30 25.50
6iv) 96.30 96.00
6iii) The elements in R represent the total cost of buying the CDs and paper at shop A or shop
B for Andrew, Betty and Charles respectively.
6v) The elements in T represent the total spent at Shop A or Shop B by Andrew, Betty and
Charles.
7bi)) 1/5 7bii) 5/13 7c) 119/1235
8a) 135o
8b) 112.5o
8d) 10.6 cm2
9bi) 9 cm 9biii) 12 10
5 cm
10i) 60o
10ii) 176 m 10iii) 19.8o
10iv) 144.5o
10v) 64.5o 11a) –3.25 11c) 3.25
11d) 16.7 11e) –0.6 , 4
Anglican High School Preliminary Examinations 2010 Mathematics Paper 2
12
AHS 2010 Prel EM P2 Solution
1 (a) A train travelled a distance of 375 km in 5 hours from Station A to Station B. After
taking a break of 45 minutes, it then travelled a further distance of 157.5 km at an
average speed of 90 km/h.
Calculate:
i) its average speed for the first part of the journey, [1]
ii) the time taken, in hours and minutes, for the second part of the journey, [1]
iii) its average speed for the whole journey. [3]
(b) Solve the equation
32−𝑥 = 1
35𝑥+13 [2]
(c) Express the following as a single fraction in its simplest form.
5 + 𝑦
25 − 𝑦2−
3
𝑦 − 5 [3]
Answer:
1a i) average speed for the first part of the journey = 375 5
= 75 km/h
ii) time taken for the second part of the journey = 157.5 90
= 1¾ h
= 1 h 45 min
iii) average speed for the whole journey
=
4
31
4
35
5.157375
= 5.75.532 = 71 km/h
Q1b) 32−𝑥 = 1
35𝑥+13
32−𝑥 = 3−(5𝑥
3 +
1
3)
2 – x = −5𝑥
3−
1
3
2𝑥
3= −
7
3
x = −7
2
Anglican High School Preliminary Examinations 2010 Mathematics Paper 2
13
Q1c) 5+𝑦
25 − 𝑦2 − 3
𝑦 − 5 =
5+𝑦
5−𝑦 (5+𝑦)+
3
5 − 𝑦
= 5 + 𝑦 + 3(5+𝑦)
5−𝑦 (5+𝑦)
= 20 + 4𝑦
5−𝑦 (5+𝑦)
= 4(5 + 𝑦)
5−𝑦 (5+𝑦)
= 4
5−𝑦
2 (a) A soccer club has 150 members. X is the set of strikers. Y is the set of defenders.
The letters a, b and c in the Venn diagram represent the number of members in
each of the subsets of X and Y. The letter d represents the numbers of members
who are neither strikers nor defenders. Given that n(X) = 90 and n(Y) = 68, find
(i) the value of b if d = 0, [1]
(ii) the value of d if b = c, [1]
(iii) the largest possible number of members who are neither strikers nor
defenders. [1]
2a i)
When d = 0, 90+ 68 – b = 150
b = 8
ii) When b = c, b = c = (68÷ 2) = 34
Therefore, a – b + b + c + d = 150
90 + 34 + d =150
d = 26
iii) Largest possible value of members who are neither strikers nor
defenders is when Y becomes a proper subset of X.
Therefore d + a = 150
Largest value of d = 150 – 90 = 60
X Y
a b
c
d
Anglican High School Preliminary Examinations 2010 Mathematics Paper 2
14
2 (b) The table below shows the number of pens own by each student in a class.
Number of pens 0 1 2 3 4 5
Number of students 1 3 x 7 5 2
(i) If the mode of the distribution is 3, find the range of values of x. [1]
(ii) If the median is 3, what is the largest value of x. [1]
(iii) If the mean is 2.9, find the value of x. [2]
54 + 2𝑥 = 52.2 + 2.9𝑥
2bi) 0 ≤ 𝑥 ≤ 6
ii) 1+3+𝑥+7+5+2+1
2 ≤ 7+5+2
19 + 𝑥 ≤ 28 𝑥 ≤ 9
Therefore, largest value of x is 9.
iii) 0+3+2𝑥+21+20+10
1+3+𝑥+7+5+2 = 2.9
54+2𝑥
18+𝑥 = 2.9
0.9𝑥 = 1.8
𝑥 = 2
Anglican High School Preliminary Examinations 2010 Mathematics Paper 2
15
3 (a) The diagram shows the arcs AB and EF
of a circle, centre O, with radius r cm.
BCX, OP and EDY are straight lines that
perpendicular to the line segment AXPYF.
Given that AX =XY =YF = 5cm,
CDYX is a rectangle with CX = 4 cm.
i) Show that r = 8.5 cm [1]
ii) Calculate the arc AB. [4]
Solution
(a) i) r = 𝐴𝑃2 + 𝑂𝑃2
= (5 + 2.5)2 + 42
= 8.5 cm (shown)
ii) COA = OAP
= tan – 1 4
7.5
= 28.07o
BOC = cos –1
2.5
8.5
= 72.89o
AOB = AOC + COB
= 28.07o + 72.89
o
= 100.96o
Arc AB = 100.96𝑜
360𝑜 2 (8.5)
= 14.97
15.0 cm
B E
C D
A X P Y F
O
Anglican High School Preliminary Examinations 2010 Mathematics Paper 2
16
3 (b) The cost price of a particular model of camera is $300. Shop A advertises its sale
as “usual price $450 now $360”. Shop B sells the same model of camera at $420
after 25% discount.
Calculate
i) the discount given by shop A as a percentage, [2]
ii) the original marked price of the camera at shop B, [1]
iii) the profit gained by shop B as a percentage. [2]
3b) i) Discount = 450−360
450 100%
= 20 %
ii) Original marked price = 420
75%
= $ 560
iii) Percentage of profit = 420−300
300 100%
= 40%
4 (a) It takes 3 hours and 10 min for 5 workers to paint a hall. Given that all the workers
work at the same rate, how long will 2 workers take to paint the same hall?
[Leave your answer in hours and minutes] [2]
4(a) No. of workers : No. of hours
= 5 : 3 1
6
= 5 2
5 :
19
6
5
2
= 2 : 95
12
= 2 : 475
60
= 2 : 7 hours 55 min
Anglican High School Preliminary Examinations 2010 Mathematics Paper 2
17
3(b) Mr Hai takes x minutes to carve a swan out of a block ice and Mr Li takes 25 more
minutes to carve an identical sculpture. If both of them work together, it only takes
30 minutes to complete carving an identical sculpture.
i) Form an equation involving x, and show that it simplifies to
x2 – 35x – 750 = 0. [2]
ii) Determine the time taken by Mr Li to carve the sculpture on his own.
[3]
4(b) 1
𝑥+
1
𝑥 + 25=
1
30
2𝑥+25
𝑥(𝑥 + 25)=
1
30
60 x + 750 = x2 + 25x
x2 – 35x – 750 = 0 (shown)
(x + 15)( x – 50) = 0
x = – 15 (rej) or x = 50
Time taken by Mr Li = 50 + 25
= 75 min
= 1 hr 15 min
4 (c) i) Solve – 4 < 2x – 5 13 [2]
ii) Write down all the prime numbers which satisfies this condition. [1]
4 (c) i) – 4 < 2x – 5 13
1 < 2x 18
½ < x 9
ii) Prime numbers are 2, 3, 5 & 7
Anglican High School Preliminary Examinations 2010 Mathematics Paper 2
18
5 The diagram shows a solid in which ABCD, DCFE and ABFE are rectangles. G is the
foot of perpendicular from D to AE. Given that AB = 5 cm, AD = 8 cm, DE = 5.5 cm
and angle DAE is 25°.
Find,
(i) the length of DG, [1]
(ii) angle DCG, [2]
(iii) the length of AE, [4]
5 (i) 𝐷𝐺
8 = sin 25
o
𝐷𝐺 = 8 × 𝑠𝑖𝑛25°
= 3.3809
≈ 𝟑.𝟑𝟖 𝒄𝒎
ii) In ΔDCG, tan DCG = 𝐷𝐺
𝐷𝐶
= 3.3809
5
∠𝐷𝐶𝐺 = 34.065𝑜
≈ 𝟑𝟒.𝟏°
C
A
B F
D
E G
5 cm 8 cm 5.5 cm
25o
Anglican High School Preliminary Examinations 2010 Mathematics Paper 2
19
iii) AG = 82 − 3.38092
= 7.250 cm
GE = 5.52 − 3.38092
= 4.338 cm
AE = AG + GE
= 7.250 + 4.338
= 11.588
11.6 cm
6 Two shops A and B sell the same brand of compact discs (CDs) and printing paper. Each
box of CDs is sold at $3.70 and $3.80 at Shop A and Shop B respectively. Each ream of
paper is sold at $6.80 and $6.50 at Shop A and Shop B respectively. The prices of the
items are represented by the matrix P,
𝑷 = $3.70 $3.80$6.80 $6.50
Andrew plans to buy 6 boxes of CDs and 2 reams of paper. Betty plans to buy 4 boxes of
CDs and 3 reams of paper. Charles plans to buy 5 boxes of CDs and 1 ream of paper.
(i) Represent the quantities of CDs and papers to be bought by the 3 persons as
a matrix Q. [1]
(ii) Evaluate the product, R = QP [2]
(iii) State what the elements of R represent. [1]
(iv) Evaluate T = (1 1 1) R. [1]
(v) State what the elements of T represent. [1]
(vi) If Andrew, Betty and Charles combine their purchase, which shop will give them a
better deal. [
Anglican High School Preliminary Examinations 2010 Mathematics Paper 2
20
6i) Q = 6 24 35 1
ii) 𝑹 = 6 24 35 1
3.70 3.806.80 6.50
= 6 × 3.7 + 2 × 6.8 6 × 3.8 + 2 × 6.54 × 3.7 + 3 × 6.8 4 × 3.8 + 3 × 6.55 × 3.7 + 1 × 6.8 5 × 3.8 + 1 × 6.5
= 35.80 35.8035.20 34.7025.30 25.50
iii) The elements in R represent the total cost of buying the CDs and paper at shop A
or shop B for Andrew, Betty and Charles respectively.
iv) 𝑻 = 1 1 1 35.80 35.8035.20 34.7025.3 25.5
= 96.30 96.00
v) The elements in T represent the total spent at Shop A or Shop B by Andrew, Betty
and Charles.
vi) Shop B
7 A bowl of sweets contains 12 chocolate nuggets, 13 mints and 15 toffees. Mr Chan takes
two sweets at random and eats them.
(a) Draw a tree diagram to represent all the possible outcome. [3]
(b) Calculate the probability, as a fraction in its simplest form, that
i) a chocolate nugget and a mint was taken. [1]
ii) none of the two sweets chosen were toffees. [1]
(c) A third sweet was randomly taken from the bowl. Calculate the probability that the
first two sweets drawn were of the same type and the third was a chocolate nugget.
[2]
Anglican High School Preliminary Examinations 2010 Mathematics Paper 2
21
7a)
bi) P(that to get chocolate and mint) =12
40×
13
39 +
13
40×
12
39 =
1
5
bii) P(none of the two sweets are toffees) = 12
40×
24
39+
13
40×
24
39 =
5
13
(c) P(two sweets of the same type and the third a chocolate nugget)
=12
40×
11
39 ×
10
38+
13
40×
12
39×
12
38+
15
40×
14
39×
12
38
= 119
1235
14
39
13
39
12
39
15
39
12
39
13
39
15
39
12
39
11
39
T
M
C
T
M
C
T
M
C
15
40
13
40
12
40
T
M
C
Anglican High School Preliminary Examinations 2010 Mathematics Paper 2
22
8. The diagram shows two regular octagons meet at points A and B.
(a) Find the size of each interior angle of the octagons.
[1]
(b) Find PAQ.
[2]
(c) Show that
𝐴𝐵
𝐴𝐶 = 1.85, correct to 3 significant figures.
[3]
(d) Hence or otherwise, find the area of the smaller octagon if the area of the bigger
octagon is 36.2 cm2.
[3]
8 (a) Interior angle = 180o – 360
o/8 = 135
o
(b) CAB = (180 – 135)
o/2 = 22.5
o
PAQ = 360o – 135
o – (135
o – 22.5
o)
= 112.5o
Q
C
B
P
A
Anglican High School Preliminary Examinations 2010 Mathematics Paper 2
23
9. The diagram shows a circle, centre O and radius 3 cm.
An inscribed triangle ABC is
drawn with A and B are on
the y-axis.
AC is extended to meet the
x-axis at D and OD meets
BC at E.
(a) Prove that triangles BOE and DOA are similar.
[3]
(b) If OE = 1 cm,
(i) find OD,
(ii) show that AC = 3 10
5 cm,
(iii) hence find the exact length of DC.
[2]
[3]
[2]
(c)
(d)
𝐴𝐵
sin 135𝑜 = 𝐴𝐶
sin 22.5𝑜
𝐴𝐵
𝐴𝐶 =
sin 135𝑜
sin 22.5𝑜
= 1.8477
1.85
The two octagons are similar objects,
area of the larger octagon
area of the smaller octagon = (
𝐴𝐵
𝐴𝐶 )2
= 1.852
area of the smaller octagon = 36.2
1.852
= 10.577
10.6 cm
y
xE
C
A
B
OD
Anglican High School Preliminary Examinations 2010 Mathematics Paper 2
24
Solution
9.
9
(a) BOE = DOA = 90o (axes are perpendicular)
ACB = 90o ( rt in a semicircle)
ABC = 180o – 90
o – BAC ( sum of )
= 90o – BAC
ADO = 180o – 90
o – BAC
= 90o – BAC
ABC = ADO
By AAA property, triangles BOE and DOA are similar.
(b) (i) Since triangles BOE and DOA are similar,
𝑂𝐷
𝑂𝐵=
𝑂𝐴
𝑂𝐸
𝑂𝐷
3=
3
1
OD = 9 cm
(ii) ABC is similar to EBO,
𝐴𝐶
𝐸𝑂=
𝐴𝐵
𝐸𝐵
𝐴𝐶
1=
6
1+9
AC = 6 10
10
= 3 10
5 cm
DC = AD – AC
= 9 + 81 – 3 10
5
= 3 10 – 3 10
5
= 12 10
5 cm
Anglican High School Preliminary Examinations 2010 Mathematics Paper 2
25
10
O, P , W and R are points on a horizontal plane. A vertical memorial tower, OT, is due
north of P. The angle of elevation of a man at P to the top of the tower is 15°. He walks a
distance of 200 metres to point W. Given that the bearing of W from P is 040° and the
bearing of O from W is 280°, calculate
i) ∠PWO, [2]
ii) OP, [2]
iii) the height of the tower OT, [2]
iv) the angle of depression of W from T. [2]
From W, the man walks 150 metres to a point R on a bearing of 𝜃° on the horizontal
plane. At R, the angle of elevation of the man to the top of the tower is 10°.
Calculate
v) angle OWR, [3]
vi) the value of 𝜃. [1]
Solution
N
N
R
T
O
P 150 m 200 m
15O
40O
280O
W
Anglican High School Preliminary Examinations 2010 Mathematics Paper 2
26
10 i) ∠𝑂𝑊𝑁 = 360 − 280 = 80°
∠𝑃𝑂𝑊 = 80° 𝑎𝑙𝑡 𝑎𝑛𝑔𝑙𝑒 ∠𝑃𝑊𝑂 = 180 − 80 − 40 = 60°
ii) 𝑂𝑃
sin 60 =
200
𝑠𝑖𝑛80
𝑂𝑃 = 𝑠𝑖𝑛60 ×200
𝑠𝑖𝑛80
= 175.87 ≈ 𝟏𝟕𝟔𝒎
iii) Height of Tower = 𝑂𝑃 𝑡𝑎𝑛15°
= 47.124 ≈ 𝟒𝟕.𝟏𝒎
iv) 𝑂𝑊
𝑠𝑖𝑛40𝑜 =200
sin 80𝑜
𝑂𝑊 = 200 × 𝑠𝑖𝑛40𝑜 ÷ sin 80𝑜
≈ 130.54
𝐴𝑛𝑔𝑙𝑒 𝑜𝑓 𝑑𝑒𝑝𝑟𝑒𝑠𝑠𝑖𝑜𝑛 𝑜𝑓 𝑊 𝑓𝑟𝑜𝑚 𝑇 = 𝑡𝑎𝑛−1 47.124
130.54
= 19.849° ≈ 19.8°
v) 47.124
𝑂𝑅 = tan 10o
𝑂𝑅 = 47.124 ÷ 𝑡𝑎𝑛10°
267.25
cos∠𝑂𝑊𝑅 =130.542 + 1502 − 267.252
2 × 130.54 × 150
∠𝑂𝑊𝑅 = 144.50 𝑜 ≈ 𝟏𝟒𝟒.𝟓°
vi) Value of = 144.50o – 80
o
= 64.50o
64.5o
Anglican High School Preliminary Examinations 2010 Mathematics Paper 2
27
11. Answer the whole of this question on a sheet of graph paper.
The variables x and y are connected by the equation
𝑦 = 3 2𝑥 − 4.
Some corresponding values of x and y are given in the following table.
x –2 –1 0 1 2 3 4
y a –2.5 –1 2 8 20 44
(a) Find the value of a.
[1]
(b) Using a scale of 2 cm to 1 unit, draw a horizontal x–axis for –2 ≤ x ≤ 4.
Using a scale of 2 cm to 5 units, draw a vertical y–axis for –5 ≤ y ≤ 45.
On your axes, plot the points given in the table and join them with a smooth curve.
[3]
(c) Use your graph to find the solution of 2𝑥 = 9.
[2]
(d) By drawing a tangent, find the gradient of the curve at the point (3, 20).
[2]
(e) Use your graph to find the solutions of the equation 3 2𝑥 − 10𝑥 − 8 = 0.
[3]
Anglican High School Preliminary Examinations 2010 Mathematics Paper 2
28
11. (a) 𝑎 = 3 2−2 − 4 = –3.25
(b)
(c) 2𝑥 = 9
3(2𝑥) − 4 = 3 9 − 4
3(2𝑥) − 4 = 23
From the graph, when y=23, x= 3.25
(d) gradient of the curve at the point (3, 20) 16.7
(e) 3 2𝑥 − 10𝑥 + 8 = 0
3 2𝑥 = 10𝑥 + 8
3 2𝑥 − 4 = 10𝑥 + 4
Insert 𝑦 = 10𝑥 + 4,
From the graph,
x – 0.6, 4