DSE Mathematics · Core

Past paper questions

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

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2017 · Paper 1 Q1 Formulae
(a) Make yy the subject of the formula k=3xyyk=\frac{3x-y}{y}. (3 marks)
2017 · Paper 1 Q2 Laws of integral indices
(a) Simplify (m4n1)3(m2)5 \frac{(m^{4}n^{-1})^{3}}{(m^{-2})^{5}} and express your answer with positive indices.
2017 · Paper 1 Q3 Polynomials
Factorize
(a)
(i) x24xy+3y2x^{2}-4xy+3y^{2}
(ii) x24xy+3y2+11x33yx^{2}-4xy+3y^{2}+11x-33y. (3 marks)
2017 · Paper 1 Q4 Linear equations in two unknowns
There are only two kinds of admission tickets for a theatre: regular tickets and concessionary tickets. The prices of a regular ticket and a concessionary ticket are \126and and \7878 respectively. On a certain day, the number of regular tickets sold is 5 times the number of concessionary tickets sold and the sum of money for the admission tickets sold is \50,976$. Find the total number of admission tickets sold that day. (4 marks)
2017 · Paper 1 Q5 Linear inequalities in one unknown
(a) Find the range of values of xx which satisfy both 7(x2)11x+837(x-2)\leq\frac{11x+8}{3} and 6x<56-x<5.
(b) How many integers satisfy both inequalities in (a)?

(4 marks)
2017 · Paper 1 Q6 Equations of straight lines
(a) Write down the coordinates of AA' and BB'.
(b) Prove that ABAB is perpendicular to ABA'B'.

(4 marks)
2017 · Paper 1 Q7 Presentation of data
The pie chart below shows the distribution of the seasons of birth of the students in a school.

Distribution of the seasons of birth of the students in the school

If a student is randomly selected from the school, then the probability that the selected student was born in spring is 19\frac{1}{9}.
Figure
(a) Find xx.
(b) In the school, there are 180180 students born in winter. Find the number of students in the school. (4 marks)
2017 · Paper 1 Q8 Variations
It is given that yy varies inversely as x\sqrt{x}. When x=144x=144, y=81y=81.
(a) Express yy in terms of xx.
(b) If the value of xx is increased from 144144 to 324324, find the change in the value of yy. (5 marks)
2017 · Paper 1 Q9 Errors in measurement
(a) Find the least possible capacity of a standard bottle.
(b) Someone claims that the total capacity of 120120 standard bottles can be measured as 23.323.3 L correct to the nearest 0.10.1 L. Do you agree? Explain your answer. (5 marks)
2017 · Paper 1 Q10 Congruent triangles
In Figure 1, OPQROPQR is a quadrilateral such that OP=OQ=OROP = OQ = OR. OQOQ and PRPR intersect at the point SS. SS is the mid-point of PRPR.
Figure
(a) Prove that ΔOPSΔORS\Delta OPS \cong \Delta ORS.
(i)
(b) It is given that OO is the centre of the circle which passes through PP, QQ and RR. If OQ=6OQ=6 cm and PRQ=10\angle PRQ=10^{\circ}, find the area of the sector OPQROPQR in terms of π\pi.
(i)
2017 · Paper 1 Q11 Measures of dispersion
The stem-and-leaf diagram below shows the distribution of the hourly wages (in dollars) of the workers in a group.

Stem (tens) | Leaf (units)
6 | 1 1 1 3 4 6 8 9 9
7 | a 7 7 8
8 | 1 b

It is given that the mean and the range of the above distribution are 70and70 and 22 respectively.
(a) Find the median and the standard deviation of the above distribution. (5 marks)
(b) If a worker is randomly selected from the group, find the probability that the hourly wage of the selected worker exceeds $70 . (2 marks)
2017 · Paper 1 Q12 Mensuration
A solid metal right prism of base area 84extcm284 ext{ cm}^{2} and height 20extcm20 ext{ cm} is melted and recast into two similar solid right pyramids. The bases of the two pyramids are squares. The ratio of the base area of the smaller pyramid to the base area of the larger pyramid is 4:94:9.
(a) Find the volume of the larger pyramid. (3 marks)
(b) If the height of the larger pyramid is 12extcm12 ext{ cm}, find the total surface area of the smaller pyramid. (4 marks)
2017 · Paper 1 Q13 Equations of circles
The coordinates of the points EE, FF and GG are (6,5)(-6,5), (3,11)(-3,11) and (2,1)(2,-1) respectively. The circle CC passes through EE and the centre of CC is GG.
(a) Find the equation of CC.
(b) Prove that FF lies outside CC. (2 marks)
(c) Let HH be a moving point on CC. When HH is farthest from FF,
(i) describe the geometric relationship between FF, GG and HH;
(ii) find the equation of the straight line which passes through FF and HH.
2017 · Paper 1 Q14 More about polynomials
(a) Find aa.
(b) Let g(x)g(x) be a quadratic polynomial such that when g(x)g(x) is divided by 2x2+ax+42x^{2} + ax + 4, the remainder is bx+cbx + c.
(i) Prove that f(x)g(x)f(x) - g(x) is divisible by 2x2+ax+42x^{2} + ax + 4.
(ii) Someone claims that all the roots of the equation f(x)g(x)=0f(x) - g(x) = 0 are integers. Do you agree? Explain your answer. (5 marks)
2017 · Paper 1 Q15 Exponential and logarithmic functions
Let aa and bb be constants. Denote the graph of y=a+logbxy = a + \log_{b}x by GG. The xx-intercept of GG is 9 and GG passes through the point (243,3)(243, 3).
() Express xx in terms of yy. (4 marks)
2017 · Paper 1 Q16 Arithmetic and geometric sequences and their summations
A city adopts a plan to import water from another city. It is given that the volume of water imported in the 1st year since the start of the plan is 1.5×107m3 1.5 \times 10^7 \, \text{m}^3 and in subsequent years, the volume of water imported each year is 10%10\% less than the volume of water imported in the previous year.
(a) Find the total volume of water imported in the first 20 years since the start of the plan. (2 marks)
(b) Someone claims that the total volume of water imported since the start of the plan will not exceed 1.6×108 1.6 \times 10^{8} m 3 ^{3} . Do you agree? Explain your answer. (2 marks)
2017 · Paper 1 Q17 More about probability
(a) find the probability that exactly 4 green pens are drawn; (2 marks)
(b) find the probability that exactly 3 green pens are drawn; (2 marks)
(c) find the probability that exactly 5 green pens are drawn. (2 marks)
(d) find the probability that not more than 2 green pens are drawn. (2 marks)
2017 · Paper 1 Q18 More about equations
The equation of the parabola Γ\Gamma is y=2x22kx+2x3k+8y=2x^{2}-2kx+2x-3k+8, where kk is a real constant. Denote the straight line y=19y=19 by LL.
(a) Prove that LL and Γ\Gamma intersect at two distinct points. (3 marks)
(b) The points of intersection of LL and Γ\Gamma are AA and BB.
(i) Let aa and bb be the xx-coordinates of AA and BB respectively. Prove that (ab)2=k2+4k+23(a-b)^{2}=k^{2}+4k+23.
(ii) Is it possible that the distance between AA and BB is less than 44? Explain your answer. (5 marks)
2017 · Paper 1 Q19 Trigonometry
ABC is a thin triangular metal sheet, where BC=24 cmBC = 24\text{ cm}, BAC=30\angle BAC = 30^\circ and ACB=42\angle ACB = 42^\circ.
Figure
(a) Find the length of ACAC.

(2 marks)
(b) In Figure 2, the thin metal sheet ABCABC is held such that only the vertex BB lies on the horizontal ground. DD and EE are points lying on the horizontal ground vertically below the vertices AA and CC respectively. ACAC produced meets the horizontal ground at the point FF. A craftsman finds that AD=10 cmAD=10\text{ cm} and CE=2 cmCE=2\text{ cm}.
Figure
(i) Find the distance between CC and FF.
(ii) Find the area of ΔABF\Delta ABF.
(iii) Find the inclination of the thin metal sheet ABCABC to the horizontal ground.
(iv) The craftsman claims that the area of ΔBDF\Delta BDF is greater than 460 cm2460\text{ cm}^{2}. Do you agree?

(11 marks)
2017 · Paper 2 Q1 Algebraic expressions
3m25mn+2n2+mn= 3m^{2}-5mn+2n^{2}+m-n=
A (mn)(3m2n+1) (m-n)(3m-2n+1)
B (mn)(3m+2n+1) (m-n)(3m+2n+1)
C (m+n)(3m2n1) (m+n)(3m-2n-1)
D (m+n)(3m+2n1) (m+n)(3m+2n-1)
2017 · Paper 2 Q2 Laws of integral indices
(19555)3444= \left(\frac{1}{9^{555}}\right)3^{444}=
A 0. 0.
B 13111 \frac{1}{3^{111}}
C 13222 \frac{1}{3^{222}}
D 13666 \frac{1}{3^{666}}
2017 · Paper 2 Q3 Linear equations in one unknown
If a+4b2a=2+ba \frac{a+4b}{2a}=2+\frac{b}{a} , then a= a=
A 2b3 \frac{2b}{3}
B 3b2 \frac{3b}{2}
C 5b6 \frac{5b}{6}
D 6b5 \frac{6b}{5}
2017 · Paper 2 Q4 Approximate values and numerical estimation
1π4=\frac{1}{\pi^{4}} =
A 0.01020.0102 (correct to 3 significant figures).
B 0.010250.01025 (correct to 4 significant figures).
C 0.010260.01026 (correct to 5 decimal places).
D 0.0102660.010266 (correct to 6 decimal places).
2017 · Paper 2 Q5 Linear inequalities in one unknown
The solution of 6x<2x36-x<2x-3 or 73x>17-3x>1 is
A x<2x<2
B x>3x>3
C 2<x<32<x<3
D x<2x<2 or x>3x>3
2017 · Paper 2 Q6 Polynomials
Let kk be a constant. If f(x)=2x25x+kf(x)=2x^{2}-5x+k, then f(2)f(2)=f(2)-f(-2)=
A 20-20.
B 00.
C 1616.
D 2k2k.
2017 · Paper 2 Q7 More about polynomials
Let p(x)=2x211x+cp(x)=2x^{2}-11x+c, where cc is a constant. If p(x)p(x) is divisible by x7x-7, find the remainder when p(x)p(x) is divided by 2x+12x+1.
A 26-26
B 15-15
C 1515
D 2626
2017 · Paper 2 Q8 Identities
If mm and nn are constants such that 4x2+m(x+1)+28=mx(x+3)+n(x4)4x^{2}+m(x+1)+28=mx(x+3)+n(x-4), then n=n=
A 8-8.
B 7-7.
C 44.
D 1616.
2017 · Paper 2 Q9 Functions and graphs
The figure shows the graph of y=(px+5)2+qy=(px+5)^{2}+q, where pp and qq are constants. Which of the following is true?
Figure
A p<0p<0 and q<0q<0
B p<0p<0 and q>0q>0
C p>0p>0 and q<0q<0
D p>0p>0 and q>0q>0
2017 · Paper 2 Q10 Using percentages
A sum of \2\,000isdepositedataninterestrateof is deposited at an interest rate of 5\%perannumfor per annum for 4$ years, compounded half-yearly. Find the interest correct to the nearest dollar.
A \400$
B \431$
C \437$
D \440$
2017 · Paper 2 Q11 Rates, ratios and proportions
The scale of a map is 1:200001:20\,000. If the area of a zoo on the map is 4 cm24\text{ cm}^{2}, then the actual area of the zoo is
A 8×104 m28\times10^{4}\text{ m}^{2}.
B 1.6×105 m21.6\times10^{5}\text{ m}^{2}.
C 3.2×105 m23.2\times10^{5}\text{ m}^{2}.
D 1×106 m21\times10^{6}\text{ m}^{2}.
2017 · Paper 2 Q12 Variations
It is given that yy is the sum of two parts, one part is a constant and the other part varies as x2x^{2}. When x=1x=1, y=7y=7 and when x=2x=2, y=13y=13. If x=3x=3, then y=y=
A 1919.
B 2020.
C 2323.
D 4747.
2017 · Paper 2 Q13 Arithmetic and geometric sequences and their summations
In the figure, the 1st pattern consists of 1 dot. For any positive integer nn, the (n+1)(n+1)th pattern is formed by adding (2n+2)(2n+2) dots to the nnth pattern. Find the number of dots in the 7th pattern.
Figure
A 4141
B 5555
C 7171
D 161161
2017 · Paper 2 Q14 Mensuration
In the figure, DD is a point lying on ACAC such that BDBD is perpendicular to ACAC. It is given that AC=14 cmAC=14\text{ cm} and BD=12 cmBD=12\text{ cm}. If the area of ABD\triangle ABD is greater than the area of BCD\triangle BCD by 24 cm224\text{ cm}^{2}, then the perimeter of ABC\triangle ABC is
Figure
A
B
C
D
2017 · Paper 2 Q15 Mensuration
The base radius of a right circular cone is 2 times the base radius of a right circular cylinder while the height of the circular cylinder is 3 times the height of the circular cone. If the volume of the circular cone is 36π cm336\pi\ \text{cm}^{3}, then the volume of the circular cylinder is
A 27π cm327\pi\ \text{cm}^{3}
B 48π cm348\pi\ \text{cm}^{3}
C 81π cm381\pi\ \text{cm}^{3}
D 144π cm3144\pi\ \text{cm}^{3}
2017 · Paper 2 Q16 More about equations
In the figure, ABCDABCD and BEDFBEDF are parallelograms. EE is a point lying on BCBC such that BE:EC=2:3BE:EC=2:3. ACAC cuts BFBF and DEDE at GG and HH respectively. If the area of ABG\triangle ABG is 135 cm2135\mathrm{~cm}^{2}, then the area of the quadrilateral DFGHDFGH is
Figure
A 60 cm260\ \text{cm}^{2}
B 81 cm281\ \text{cm}^{2}
C 90 cm290\ \text{cm}^{2}
D 144 cm2144\ \text{cm}^{2}
2017 · Paper 2 Q17 More about trigonometry
In the figure, ABCABC is an equilateral triangle of side 16 cm16\mathrm{~cm}. DD and EE are points lying on ABAB and BCBC respectively such that AD=4 cmAD=4\mathrm{~cm} and CDE=60\angle CDE=60^{\circ}. Find CECE.
Figure
A 9 cm9\ \text{cm}
B 10 cm10\ \text{cm}
C 12 cm12\ \text{cm}
D 13 cm13\ \text{cm}
2017 · Paper 2 Q18 Angles and parallel lines
In the figure, AB=BCAB = BC and DD is a point lying on AEAE such that AC=ADAC = AD. If AEBCAE \parallel BC, then ABC=\angle ABC =
Figure
A 4444^{\circ}.
B 5656^{\circ}.
C 6262^{\circ}.
D 6868^{\circ}.
2017 · Paper 2 Q19 Rectangular coordinate system
In the figure, the length of the line segment joining A and H is
Figure
A 6.
B 8.
C 9.
D 10.
2017 · Paper 2 Q20 Quadrilaterals
ABCDABCD is a parallelogram. Let EE be the mid-point of ADAD. If ABE=CBD=DBE\angle ABE = \angle CBD = \angle DBE, which of the following are true?
A I and II only
B I and III only
C II and III only
D I, II and III
2017 · Paper 2 Q21 Basic properties of circles
In the figure, ADAD is a diameter of the circle ABCDEABCDE. If BC=CDBC = CD and ABC=110\angle ABC = 110^{\circ}, then BED=\angle BED =
Figure
A 2020^{\circ}.
B 3535^{\circ}.
C 4040^{\circ}.
D 5555^{\circ}.
2017 · Paper 2 Q22 Trigonometry
In the figure, ABCDABCD is a rectangle. If EE is a point lying on CDCD such that CBE=40\angle CBE=40^{\circ}, find AED\angle AED correct to the nearest degree.
Figure
A 3333^{\circ}
B 4343^{\circ}
C 4747^{\circ}
D 5757^{\circ}
2017 · Paper 2 Q23 Equations of straight lines
In the figure, the equations of the straight lines L1L_{1} and L2L_{2} are x+my=nx + my = n and x+py=qx + py = q respectively. Which of the following are true?
Figure
I m<pm < p
II n>qn > q
III n+m<p+qn + m < p + q
A I and II only
B I and III only
C II and III only
D I, II and III
2017 · Paper 2 Q24 Equations of straight lines
The straight line L is perpendicular to the straight line 9x5y+45=09x - 5y + 45 = 0. If the xx-intercept of L is 3-3, then the equation of L is
A 5x+9y+15=05x + 9y + 15 = 0
B 5x+9y+27=05x + 9y + 27 = 0
C 9x5y+15=09x - 5y + 15 = 0
D 9x5y+27=09x - 5y + 27 = 0
2017 · Paper 2 Q25 Trigonometry
The polar coordinates of the points PP, QQ and RR are (3,160)(3,160^{\circ}), (4,280)(4,280^{\circ}) and (6,340)(6,340^{\circ}) respectively. The perpendicular distance from QQ to PRPR is
A 22.
B 33.
C 232\sqrt{3}
D 333\sqrt{3}
2017 · Paper 2 Q26 Equations of circles
The equations of the circles C1C_{1} and C2C_{2} are x2+y2+8x4y5=0x^{2}+y^{2}+8x-4y-5=0 and 2x2+2y2+8x4y5=02x^{2}+2y^{2}+8x-4y-5=0 respectively. Let G1G_{1} and G2G_{2} be the centres of C1C_{1} and C2C_{2} respectively. Denote the origin by OO. Which of the following is/are true?

I. G1G_{1}, G2G_{2} and OO are collinear.

II. The radii of C1C_{1} and C2C_{2} are equal.

III. OO is equidistant from G1G_{1} and G2G_{2}.
A I only
B II only
C I and III only
D II and III only
2017 · Paper 2 Q27 Loci
It is given that AA and BB are two distinct points lying on the circle x2+y26x4y87=0x^{2}+y^{2}-6x-4y-87=0. Let PP be a moving point in the rectangular coordinate plane such that AP=BPAP=BP. The equation of the locus of PP is x+2y+k=0x+2y+k=0, where kk is a constant. Find kk.
A 8-8
B 7-7
C 77
D 88
2017 · Paper 2 Q28 Probability
The bar chart below shows the distribution of the numbers of tokens got by a group of children in a game. If a child is randomly selected from the group, find the probability that the selected child gets fewer than 5 tokens in the game.
Figure
A 23\frac{2}{3}
B 25\frac{2}{5}
C 512\frac{5}{12}
D 725\frac{7}{25}
2017 · Paper 2 Q29 Measures of dispersion
The box-and-whisker diagram below shows the distribution of the numbers of online hours spent by a class of students in a certain week. Find the lower quartile of the distribution.
Figure
A 55
B 1515
C 2525
D 4040
2017 · Paper 2 Q30 Measures of central tendency
Consider the following positive integers:

22 33 44 66 77 99 1010

Let aa, bb and cc be the modes, the median and the range of the above positive integers respectively. If the mean of the above positive integers is 55, which of the following must be true?

I. a=2a=2

II. b=4b=4

III. c=8c=8
A I only
B II only
C I and III only
D II and III only
2017 · Paper 2 Q31 More about graphs of functions
The figure above shows the graph of y=f(x)y = f(x). If g(x)=f(x2)g(x) = f\left(\frac{x}{2}\right), which of the following may represent the graph of y=g(x)y = g(x)?
FigureFigureFigureFigureFigure
A
B
C
D