DSE Mathematics · Core

Past paper questions

Sample · Practise · Paper 1 & Paper 2 · 2012–2024

Topic
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2014 · Paper 1 Q1 Laws of integral indices

Simplify (xy2)3y4\frac{(xy^{-2})^{3}}{y^{4}} and express your answer with positive indices. (3 marks)

2014 · Paper 1 Q2 More about polynomials
(a)

a22a3a^{2}-2a-3

(b)

ab2+b2+a22a3a b^{2}+b^{2}+a^{2}-2a-3 (3 marks)

2014 · Paper 1 Q3 Approximate values and numerical estimation
(a)

Round up 123.45 to 1 significant figure.

(b)

Round off 123.45 to the nearest integer.

(c)

Round down 123.45 to 1 decimal place. (3 marks)

2014 · Paper 1 Q4 Organisation of data

The table below shows the distribution of the numbers of calculators owned by some students.

2014 · Paper 1 Q5 Formulae

Consider the formula 2(3m+n)=m+72(3m+n)=m+7.

(a)

Make nn the subject of the above formula.

(b)

If the value of mm is increased by 22, write down the change in the value of nn. (4 marks)

2014 · Paper 1 Q6 Using percentages

The marked price of a toy is $255$255. The toy is now sold at a discount of 40%40\% on its marked price.

(a)

Find the selling price of the toy.

(b)

If the percentage profit is 2%2\%, find the cost of the toy. (4 marks)

2014 · Paper 1 Q7 More about polynomials
(a)

Is x+1x+1 a factor of f(x)f(x)? Explain your answer.

(b)

Someone claims that all the roots of the equation f(x)=0f(x) = 0 are rational numbers. Do you agree? Explain your answer. (5 marks)

2014 · Paper 1 Q8 Rectangular coordinate system

The coordinates of the points PP and QQ are (3,5)(-3,5) and (2,7)(2,-7) respectively. PP is rotated anticlockwise about the origin OO through 270270^{\circ} to PP^{\prime}. QQ is translated leftwards by 21 units to QQ^{\prime}.

(a)

Write down the coordinates of PP' and QQ'

(b)

Prove that PQ is perpendicular to P'Q'

2014 · Paper 1 Q9 Similar triangles

In Figure 1, DD is a point lying on ACAC such that BAC=CBD\angle BAC = \angle CBD.

Figure
(a)

Prove that ΔABCΔBDC\Delta ABC \sim \Delta BDC.

(b)

Suppose that AC=25cmAC = 25 \, \text{cm}, BC=20cmBC = 20 \, \text{cm} and BD=12cmBD = 12 \, \text{cm}. Is ΔBCD\Delta BCD a right-angled triangle? Explain your answer. (5 marks)

2014 · Paper 1 Q10 Functions and graphs

Town X and town Y are 8080 km apart. Figure 2 shows the graphs for car AA and car BB travelling on the same straight road between town XX and town YY during the period 7:30 to 9:30 in a morning. Car AA travels at a constant speed during the period. Car BB comes to rest at 8:15 in the morning.

Figure
(a)

Find the distance of car AA from town XX at 8:15 in the morning. (2 marks)

(b)

At what time after 7:30 in the morning do car AA and car BB first meet? (2 marks)

(c)

The driver of car BB claims that the average speed of car BB is higher than that of car AA during the period 8:15 to 9:30 in the morning. Do you agree? Explain your answer. (2 marks)

2014 · Paper 1 Q11 Measures of dispersion

There are 33 paintings in an art gallery. The box-and-whisker diagram below shows the distribution of the prices (in thousand dollars) of the paintings in the art gallery. It is given that the mean of this distribution is 5353 thousand dollars.

Figure
(a)

Find the range and the inter-quartile range of the above distribution. (3 marks)

(b)

Four paintings of respective prices (in thousand dollars) 3232, 3434, 5858 and 5959 are now donated to a museum. Find the mean and the median of the prices of the remaining paintings in the art gallery. (3 marks)

2014 · Paper 1 Q12 Equations of circles

The circle CC passes through the point A(6,11)A(6,11) and the centre of CC is the point G(0,3)G(0,3).

(a)

Find the equation of CC. (2 marks)

(b)

PP is a moving point in the rectangular coordinate plane such that AP=GPAP = GP. Denote the locus of PP by Γ\Gamma.

(i)

Find the equation of Γ\Gamma.

(ii)

Describe the geometric relationship between Γ\Gamma and the line segment AGAG.

(iii)

If Γ\Gamma cuts CC at QQ and RR, find the perimeter of the quadrilateral AQGRAQGR. (5 marks)

2014 · Paper 1 Q13 Variations

It is given that f(x)f(x) is the sum of two parts, one part varies as x2x^{2} and the other part is a constant. Suppose that f(2)=59f(2)=59 and f(7)=121f(7)=-121.

(a)

Find f(6)f(6).

(b)

A(6,a)A(6, a) and B(6,b)B(-6, b) are points lying on the graph of y=f(x)y = f(x). Find the area of ΔABC\Delta ABC, where CC is a point lying on the xx-axis. (4 marks)

2014 · Paper 1 Q14 Mensuration

Figure 3 shows a vessel in the form of a frustum which is made by cutting off the lower part of an inverted right circular cone of base radius 72 cm72\text{ cm} and height 96 cm96\text{ cm}. The height of the vessel is 60 cm60\text{ cm}. The vessel is placed on a horizontal table. Some water is now poured into the vessel. John finds that the depth of water in the vessel is 28 cm28\text{ cm}.

Figure
(a)

Find the area of the wet curved surface of the vessel in terms of π\pi.

(b)

John claims that the volume of water in the vessel is greater than 0.1 m30.1\text{ m}^{3}. Do you agree? Explain your answer. (4 marks)

2014 · Paper 1 Q15 Exponential and logarithmic functions

The graph in Figure 4 shows the linear relation between log4x\log_{4}x and log8y\log_{8}y. The slope and the intercept on the horizontal axis of the graph are 13\frac{-1}{3} and 3 respectively. Express the relation between xx and yy in the form y=Axky=Ax^{k}, where AA and kk are constants. (3 marks)

Figure
2014 · Paper 1 Q16 Arithmetic and geometric sequences and their summations

In Figure 5, the 1st pattern consists of 3 dots. For any positive integer nn, the (n+1)(n+1)th pattern is formed by adding 2 dots to the nnth pattern. Find the least value of mm such that the total number of dots in the first mm patterns exceeds 68886888. (4 marks)

Figure
2014 · Paper 1 Q17 Trigonometry

Figure 6(a) shows a solid pyramid VABCD with a rectangular base, where AB=18 cmAB = 18\text{ cm}, BC=10 cmBC = 10\text{ cm}, VB=VC=30 cmVB = VC = 30\text{ cm} and VAB=VDC=110\angle VAB = \angle VDC = 110^\circ.

FigureFigure
(a)

Find VBA\angle VBA.

(b)

PP, QQ, MM and NN are the mid-points of ABAB, CDCD, VBVB and VCVC respectively. A geometric model is made by cutting off PBCQNMPBCQNM from VABCDVABCD as shown in Figure 6(b). A craftsman claims that the area of the trapezium PQNMPQNM is less than 70 cm270\text{ cm}^2. Do you agree? Explain your answer. (5 marks)

2014 · Paper 1 Q18 Inequalities and linear programming
Figure
(a)

In Figure 7, the equation of the straight line L1L_{1} is 6x+7y=9006x + 7y = 900 and the x-intercept of the straight line L2L_{2} is 180. L1L_{1} and L2L_{2} intersect at the point (45,90)(45, 90). The shaded region (including the boundary) represents the solution of a system of inequalities. Find the system of inequalities. (4 marks)

(b)

A factory produces two types of wardrobes, X and Y. Each wardrobe X requires 6 man-hours for assembly and 2 man-hours for packing while each wardrobe Y requires 7 man-hours for assembly and 3 man-hours for packing. In a certain month, the factory has 900 man-hours available for assembly and 360 man-hours available for packing. The profits for producing a wardrobe X and a wardrobe Y are $440$440 and $665$665 respectively. A worker claims that the total profit can exceed $80,000$80,000 that month. Do you agree? Explain your answer. (4 marks)

2014 · Paper 1 Q19 Probability
(a)

Find the probability that Ada wins the first round of the game. (3 marks)

(b)

In the second round of the game, balls are dropped one by one into a device containing eight tubes arranged side by side (see Figure 8). When a ball is dropped into the device, it falls randomly into one of the tubes. Each tube can hold at most three balls. The player of this round adopts one of the following two options. Option 1: Two balls are dropped one by one into the device. If the two balls fall into the same tube, then the player gets 10 tokens. If the two balls fall into two adjacent tubes, then the player gets 5 tokens. Otherwise, the player gets no tokens. Option 2: Three balls are dropped one by one into the device. If the three balls fall into the same tube, then the player gets 50 tokens. If the three balls fall into three adjacent tubes, then the player gets 10 tokens. If the three balls fall into two adjacent tubes, then the player gets 5 tokens. Otherwise, the player gets no tokens.

Figure
(i)

If the player of the second round adopts Option 1, find the expected number of tokens got.

(ii)

Which option should the player of the second round adopt in order to maximise the expected number of tokens got? Explain your answer.

(iii)

Only the winner of the first round plays the second round. It is given that the player of the second round adopts the option which can maximise the expected number of tokens got. Billy claims that the probability of Ada getting no tokens in the game exceeds 0.90.9. Is the claim correct? Explain your answer. (10 marks)

2014 · Paper 1 Q1 Laws of integral indices

(2n3)5=(2n^{3})^{-5}=

A

132n2\frac{1}{32n^{2}}

B

132n15\frac{1}{32n^{15}}

C

110n125\frac{1}{10n^{125}}

D

110n243\frac{1}{10n^{243}}

2014 · Paper 1 Q2 Identities

u2v25u+5v=u^{2}-v^{2}-5u+5v=

A

(uv)(u+v5)(u-v)(u+v-5)

B

(uv)(u+v+5)(u-v)(u+v+5)

C

(u+v)(uv5)(u+v)(u-v-5)

D

(u+v)(uv+5)(u+v)(u-v+5)

2014 · Paper 1 Q3 Identities

If p and q are constants such that px(x1)+x2qx(x2)+4xpx(x-1)+x^{2} \equiv qx(x-2)+4x, then p =

A
B
C
D
2014 · Paper 1 Q4 Quadratic equations in one unknown

Let aa be a constant. If the quadratic equation x2+ax+a=1x^{2}+ax+a=1 has equal roots, then a=a=

A

1-1.

B

22.

C

00 or 4-4.

D

00 or 44.

2014 · Paper 1 Q5 More about graphs of functions

The figure shows the graph of y=mx2+x+ny = mx^2 + x + n, where mm and nn are constants. Which of the following is true?

Figure
A

m<0m < 0 and n<0n < 0

B

m<0m < 0 and n>0n > 0

C

m>0m > 0 and n<0n < 0

D

m>0m > 0 and n>0n > 0

2014 · Paper 1 Q6 Inequalities and linear programming

If a>ba>b and k<0k<0, which of the following must be true?

I. a2>b2a^{2}>b^{2}

II. a+k>b+ka+k>b+k

III. ak2>bk2\frac{a}{k^{2}}>\frac{b}{k^{2}}

A

I only

B

II only

C

I and III only

D

II and III only

2014 · Paper 1 Q7 Inequalities and linear programming

The solution of 3x<6<2x-3x<6<2x is

A

x>2x>-2

B

x>0x>0

C

x>3x>3

D

2<x<3-2<x<3

2014 · Paper 1 Q8 Linear equations in two unknowns

The price of 2 bowls and 3 cups is $506$506. If the price of 5 bowls and the price of 4 cups are the same, then the price of a bowl is

A

$88$88.

B

$92$92.

C

$110$110.

D

$115$115.

2014 · Paper 1 Q9 Using percentages

There are 792 workers in a factory. If the number of male workers is 20%20\% less than that of female workers, then the number of male workers is

A
B
C
D
2014 · Paper 1 Q10 Arc lengths and areas of sectors

If the angle and the radius of a sector are decreased by x%x\% and 50%50\% respectively so that its area is decreased by 90%90\%, then x=x=

A
B
C
D
2014 · Paper 1 Q11 Errors in measurement

The width and the length of a thin rectangular metal sheet are measured as 8 cm8\text{ cm} and 10 cm10\text{ cm} correct to the nearest cm\text{cm} respectively. Let x cm2x\text{ cm}^{2} be the actual area of the metal sheet. Find the range of values of xx.

A

71.25qx<89.2571.25 \le q x < 89.25

B

71.25<xq89.2571.25 < x \le q 89.25

C

79.5qx<80.579.5 \le q x < 80.5

D

79.5<xq80.579.5 < x \le q 80.5

2014 · Paper 1 Q12 Rates, ratios and proportions

It is given that 45a=57b=79c\frac{4}{5a} = \frac{5}{7b} = \frac{7}{9c}, where aa, bb and cc are positive numbers. Which of the following is true?

A

a<b<ca < b < c

B

a<c<ba < c < b

C

b<a<cb < a < c

D

b<c<ab < c < a

2014 · Paper 1 Q13 Variations

If z varies inversely as x and directly as the cube of y, which of the following must be constant?

A

xy3zxy^{3}z

B

x3yz3x^{3}yz^{3}

C

y3xz\frac{y^{3}}{xz}

D

yx3z3\frac{y}{x^{3}z^{3}}

2014 · Paper 1 Q14 Arithmetic and geometric sequences and their summations

Let ana_n be the nnth term of a sequence. If a2=7a_2 = 7, a4=63a_4 = 63 and an+2=an+1+ana_{n+2} = a_{n+1} + a_n for any positive integer nn, then a5=a_5 =

A
B
C
D
2014 · Paper 1 Q15 Mensuration

In the figure, AB = AE and BAE=BCD=CDE=90\angle BAE = \angle BCD = \angle CDE = 90^\circ. If BC = CD = DE = 16 cm 16\text{ cm }, then the area of the pentagon ABCDE is

Figure
A

71 cm271\ cm^{2}

B

128 cm2128\ cm^{2}

C

192 cm2192\ cm^{2}

D

224 cm2224\ cm^{2}

2014 · Paper 1 Q16 Quadrilaterals

In the figure, ABCDABCD is a square. BCBC is produced to GG such that CDG=25\angle CDG = 25^\circ. EE is a point lying on ABAB such that AE=CGAE = CG. If FF is a point lying on BCBC such that CDF=20\angle CDF = 20^\circ, then DFE=\angle DFE =

Figure
A

6060^{\circ}.

B

6565^{\circ}.

C

7070^{\circ}.

D

7373^{\circ}.

2014 · Paper 1 Q17 Similar triangles

In the figure, B is a point lying on AC such that AB:BC=3:2AB:BC = 3:2. It is given that AE//BDAE//BD. If the area of BCD\triangle BCD and the area of CDE\triangle CDE are 4 cm24\text{ cm}^{2} and 8 cm28\text{ cm}^{2} respectively, then the area of the trapezium ABDE is

Figure
A

18cm218\mathrm{cm}^{2}.

B

21cm221\mathrm{cm}^{2}.

C

27cm227\mathrm{cm}^{2}.

D

33cm233\mathrm{cm}^{2}.

2014 · Paper 1 Q18 Trigonometry

In the figure, ABD=ADC=BCD=90\angle ABD = \angle ADC = \angle BCD = 90^\circ. If AB=AB = \ell, then CD=CD =

Figure
A

sinθ\ell \sin \theta.

B

cosθ\ell \cos \theta.

C

sinθtanθ\ell \sin \theta \tan \theta.

D

tanθcosθ\frac{\ell \tan \theta}{\cos \theta}.

2014 · Paper 1 Q19 Trigonometry

(cos(90+θ)+1)(sin(360θ)1)=\left(\cos(90^{\circ}+\theta)+1\right)\left(\sin(360^{\circ}-\theta)-1\right)=

A

cos2θ-\cos^{2}\theta

B

sin2θ-\sin^{2}\theta

C

cos2θ\cos^{2}\theta

D

sin2θ\sin^{2}\theta

2014 · Paper 1 Q20 Basic properties of circles

In the figure, ACAC is a diameter of the circle ABCDEABCDE. If ADE=28\angle ADE = 28^{\circ}, then CBE=\angle CBE =

Figure
A

5656^{\circ}.

B

6262^{\circ}.

C

7272^{\circ}.

D

7676^{\circ}.

2014 · Paper 1 Q21 Basic properties of circles

In the figure, OO is the centre of the circle ABCDEFABCDEF. ΔPQR\Delta PQR intersects the circle at AA, BB, CC, DD, EE and FF. If QPR=38\angle QPR = 38^{\circ} and AB=CD=EFAB = CD = EF, then QOR=\angle QOR =

Figure
A

109109^{\circ}.

B

117117^{\circ}.

C

123123^{\circ}.

D

142142^{\circ}.

2014 · Paper 1 Q22 Polygons

If an interior angle of a regular nn-sided polygon is greater than an exterior angle by 100100^{\circ}, which of the following are true?

I. The value of nn is 10.

II. Each exterior angle of the polygon is 4040^{\circ}.

III. The number of axes of reflectional symmetry of the polygon is 9.

A

I and II only

B

I and III only

C

II and III only

D

I, II and III

2014 · Paper 1 Q23 Trigonometry

The rectangular coordinates of the point PP are (1,3)(-1, \sqrt{3}). If PP is reflected with respect to the xx-axis, then the polar coordinates of its image are

A

(2,210)(2,210^{\circ})

B

(2,240)(2,240^{\circ})

C

(4,210)(4,210^{\circ})

D

(4,240)(4,240^{\circ})

2014 · Paper 1 Q24 Loci

The equations of the straight lines L1L_{1} and L2L_{2} are 2x+3y=52x + 3y = 5 and 4x+6y=74x + 6y = 7 respectively. If P is a moving point in the rectangular coordinate plane such that the perpendicular distance from P to L1L_{1} is equal to the perpendicular distance from P to L2L_{2}, then the locus of P is a

A

circle.

B

square.

C

parabola.

D

straight line.

2014 · Paper 1 Q25 Linear equations in two unknowns

In the figure, the two straight lines intersect at a point on the positive y-axis. Which of the following are true?

Figure
A

I and II only

B

I and III only

C

II and III only

D

I, II and III

2014 · Paper 1 Q26 Equations of circles

If a diameter of the circle x2+y28x+ky214=0x^{2}+y^{2}-8x+ky-214=0 passes through the point (6,5)(6,-5) and the slope of the diameter is 4-4, then k=k=

A

6-6.

B

4-4.

C

1313.

D

7070.

2014 · Paper 1 Q27 Probability

A box contains mm yellow balls and 2020 black balls. If a ball is randomly drawn from the box, then the probability of drawing a yellow ball is 1m\frac{1}{m}. Find the value of mm.

A

44

B

55

C

1515

D

2525

2014 · Paper 1 Q28 Measures of central tendency

The mean height of 25 teachers and 140 students is 150 cm150\text{ cm}. If the mean height of the students is 145 cm145\text{ cm}, then the mean height of the teachers is

A

151 cm151\text{ cm}.

B

155 cm155\text{ cm}.

C

176 cm176\text{ cm}.

D

178 cm178\text{ cm}.

2014 · Paper 1 Q29 Presentation of data

The pie chart below shows the expenditure of John in a certain week. John spends $240$240 on clothing that week. Find his expenditure on transportation that week.

Figure
A

$40$40

B

$60$60

C

$90$90

D

$135$135

2014 · Paper 1 Q30 Measures of dispersion

The stem-and-leaf diagram below shows the distribution of the ages of the passengers in a bus.

Stem(tens)Leaf(units)71h462333467312226840k\begin{array}{c|ccccc}{{{\underline{S t e m}\mathrm{(t e n s)}}}}&{{{\underline{L e a f}\mathrm{(u n i t s)}}}}&{{{7}}} \\\hline {{{1}}}&{{{h}}}&{{{4}}}&{{{6}}} \\{{{2}}}&{{{3}}}&{{{3}}}&{{{3}}}&{{{4}}}&{{{6}}}&{{{7}}} \\{{{3}}}&{{{1}}}&{{{2}}}&{{{2}}}&{{{2}}}&{{{6}}}&{{{8}}} \\{{{4}}}&{{{0}}}&{{{k}}} \\\end{array}

If the range of the above distribution is at least 3333, which of the following must be true?

I. 0qhq30 \le q h \le q 3

II. 3qkq93 \le q k \le q 9

III. 3qkhq53 \le q k - h \le q 5

A

I only

B

II only

C

I and III only

D

II and III only

2014 · Paper 1 Q31 More about polynomials

The H.C.F. of 3x4y2z3x^{4}y^{2}z, 4xy5z4xy^{5}z and 6x2y36x^{2}y^{3} is

A

xy2xy^{2}

B

xy2zxy^{2}z

C

12x4y5z12x^{4}y^{5}z

D

12x7y9z212x^{7}y^{9}z^{2}