DSE Mathematics · Core

Past paper questions

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

Topic
128 questions match · Clear all
2020 · Paper 1 Q1 Laws of integral indices
() Simplify (mn2)5m4\frac{(mn^{-2})^{5}}{m^{-4}} and express your answer with positive indices.

(3 marks)
2020 · Paper 1 Q2 Polynomials
(a) α2+α6\alpha^{2}+\alpha-6
(b) α4+α36α2\alpha^{4}+\alpha^{3}-6\alpha^{2}

(3 marks)
2020 · Paper 1 Q3 Approximate values and numerical estimation
(a) Round up 534.7698 to the nearest hundred.
(b) Round down 534.7698 to 2 decimal places.
(c) Round off 534.7698 to 2 significant figures. (3 marks)
2020 · Paper 1 Q4 Rates, ratios and proportions
Let aa, bb and cc be non-zero numbers such that ab=67\frac{a}{b}=\frac{6}{7} and 3a=4c3a=4c. Find b+2ca+2b\frac{b+2c}{a+2b}. (3 marks)
2020 · Paper 1 Q5 Using percentages
In a recruitment exercise, the number of male applicants is 28%28\% more than the number of female applicants. The difference of the number of male applicants and the number of female applicants is 9191. Find the number of male applicants in the recruitment exercise. (4 marks)
2020 · Paper 1 Q6 Linear inequalities in one unknown
Consider the compound inequality

3x>7x2or5+x>4 3-x>\frac{7-x}{2}\quad or\quad5+x>4
(a) Solve (*).
(b) Write down the greatest negative integer satisfying (*). (4 marks)
2020 · Paper 1 Q7 Quadratic equations in one unknown
Let p(x)=4x2+12x+c p(x)=4x^{2}+12x+c , where c is a constant. The equation p(x)=0 p(x)=0 has equal roots. Find
(a) c,
(b) the x-intercept(s) of the graph of y=p(x)169y = p(x) - 169. (5 marks)
2020 · Paper 1 Q8 Congruent triangles
In Figure 1, BB and DD are points lying on ACAC and AEAE respectively. BEBE and CDCD intersect at the point FF. It is given that AB=BEAB = BE, BDCEBD \parallel CE, CAE=30\angle CAE = 30^\circ and ADB=42\angle ADB = 42^\circ.
Figure
(a) Find BEC\angle BEC.
(b) Let BDC=θ\angle BDC = \theta. Express CFE\angle CFE in terms of θ\theta. (5 marks)
2020 · Paper 1 Q9 Measures of dispersion
The table below shows the distribution of the numbers of subjects taken by a class of students.

[Table]
(a) Write down the mean, the median and the standard deviation of the above distribution.
(b) A new student now joins the class. The number of subjects taken by the new student is 5. Find the change in the median of the distribution due to the joining of this student. (5 marks)
2020 · Paper 1 Q10 Variations
The price of a brand X souvenir of height hh cm is \P.. \PP is partly constant and partly varies as h3h^{3}. When h=3h=3, \P=59P = 59andwhen and when h=7h = 7,, \P=691P=691.
(a) Find the price of a brand X souvenir of height 44 cm.
(b) Someone claims that the price of a brand X souvenir of height 55 cm is higher than the total price of two brand X souvenirs of height 44 cm. Is the claim correct? Explain your answer. (2 marks)
2020 · Paper 1 Q11 Organisation of data
The stem-and-leaf diagram below shows the distribution of the weights (in grams) of the letters in a bag.
(a) Find ww.
(b) If a letter is randomly chosen from the bag, find the probability that the weight of the chosen letter is not less than the mode of the distribution. (2 marks)
2020 · Paper 1 Q12 Mensuration
The height and the base radius of a solid right circular cone are 36 cm36\text{ cm} and 15 cm15\text{ cm} respectively. The circular cone is divided into three parts by two planes which are parallel to its base. The heights of the three parts are equal. Express, in terms of π\pi,
(a) the volume of the middle part of the circular cone;
(b) the curved surface area of the middle part of the circular cone. (3 marks)
(c)
2020 · Paper 1 Q13 More about polynomials
The cubic polynomial f(x)f(x) is divisible by x1x-1. When f(x)f(x) is divided by x21x^{2}-1, the remainder is kx+8kx+8, where kk is a constant.
(a) Find kk. (3 marks)
(b) It is given that x+3x+3 is a factor of f(x)f(x). When f(x)f(x) is divided by xx, the remainder is 2424. Someone claims that all the roots of the equation f(x)=0f(x)=0 are integers. Is the claim correct? Explain your answer. (5 marks)
2020 · Paper 1 Q14 Equations of circles
The coordinates of the points AA and BB are (10,0)(-10,0) and (30,0)(30,0) respectively. The circle CC passes through AA and BB. Denote the centre of CC by GG. It is given that the yy-coordinate of GG is 15-15.
(a) Find the equation of CC.
(b) The straight line LL passes through BB and GG. Another straight line \ell is parallel to LL. Let PP be a moving point in the rectangular coordinate plane such that the perpendicular distance from PP to LL is equal to the perpendicular distance from PP to \ell. Denote the locus of PP by Γ\Gamma. It is given that Γ\Gamma passes through AA.
(i) Describe the geometric relationship between Γ\Gamma and LL.
(ii) Find the equation of \ell.
(iii) Suppose that Γ\Gamma cuts CC at another point HH. Someone claims that GAH<70\angle GAH < 70^{\circ}. Do you agree? Explain your answer.
2020 · Paper 1 Q15 More about probability
In a box, there are 3 blue plates, 7 green plates and 9 purple plates. If 4 plates are randomly selected from the box at the same time, find
(a) the probability that 4 plates of the same colour are selected; (3 marks)
(b) the probability that at least 22 plates of different colours are selected. (2 marks)
2020 · Paper 1 Q16 Arithmetic and geometric sequences and their summations
The 3rd term and the 6th term of a geometric sequence are 144 and 486 respectively.
(a) Find the 1st1^{st} term of the sequence.
(b) Find the least value of n such that the sum of the first n terms of the sequence is greater than 8×10188 \times 10^{18}.
2020 · Paper 1 Q17 Functions and graphs
Let g(x)=x22kx+2k2+4g(x) = x^2 - 2kx + 2k^2 + 4, where kk is a real constant.
(a) Using the method of completing the square, express, in terms of kk, the coordinates of the vertex of the graph of y=g(x)y = g(x). (2 marks)
(b) On the same rectangular coordinate system, let DD and EE be the vertex of the graph of y=g(x+2)y = g(x + 2) and the vertex of the graph of y=g(x2)y = -g(x - 2) respectively. Is there a point FF on this rectangular coordinate system such that the coordinates of the circumcentre of ΔDEF\Delta DEF are (0,3)(0, 3)? Explain your answer. (4 marks)
2020 · Paper 1 Q18 Basic properties of circles
In Figure 2, UU, VV and WW are points lying on a circle. Denote the circle by CC. TUTU is the tangent to CC at UU such that TVWTVW is a straight line.
Figure
(a) Prove that ΔUTVΔWTU\Delta UTV \sim \Delta WTU. (2 marks)
(b) It is given that VWVW is a diameter of CC. Suppose that TU=780TU = 780 cm and TV=325TV = 325 cm.
(i) Express the circumference of CC in terms of π\pi.
(ii) Someone claims that the perimeter of ΔUVW\Delta UVW exceeds 3535 m. Do you agree? Explain your answer.
2020 · Paper 1 Q19 Trigonometry
PQRS is a quadrilateral paper card, where PQ=60PQ = 60 cm, PS=40PS = 40 cm, PQR=30\angle PQR = 30^{\circ}, PRQ=55\angle PRQ = 55^{\circ} and QPS=120\angle QPS = 120^{\circ}. The paper card is held with QR lying on the horizontal ground as shown in Figure 3.
Figure
(a) Find the length of RS.
(b) Find the area of the paper card. (2 marks)
(c) It is given that the angle between the paper card and the horizontal ground is 3232^{\circ}.
(i) Find the shortest distance from P to the horizontal ground.
(ii) A student claims that the angle between RS and the horizontal ground is at most 2020^{\circ}. Is the claim correct? Explain your answer. (7 marks)
2020 · Paper 2 Q1 Laws of integral indices
6x(3x5)2=\frac{6x}{(3x^{-5})^{-2}} =
A 54x854x^{8}.
B 2x83\frac{2x^{8}}{3}.
C 54x9\frac{54}{x^{9}}.
D 23x9\frac{2}{3x^{9}}.
2020 · Paper 2 Q2 Formulae
a(a+b)=2(ba)a(a+b)=2(b-a), then b=b=
A a2+a2+a\frac{a^{2}+a}{2+a}.
B a22a2+a\frac{a^{2}-2a}{2+a}.
C a2+2a2a\frac{a^{2}+2a}{2-a}.
D a2a2a\frac{a^{2}-a}{2-a}.
2020 · Paper 2 Q3 Algebraic expressions
54k+324k3=\frac{5}{4k+3}-\frac{2}{4k-3}=
A 12k2116k29\frac{12k-21}{16k^2-9}.
B 12k+916k29\frac{12k+9}{16k^2-9}.
C 14k2116k29\frac{14k-21}{16k^2-9}.
D 14k+916k29\frac{14k+9}{16k^2-9}.
2020 · Paper 2 Q4 More about polynomials
(3a+2b)(4a5b)a(6a+4b)=(3a+2b)(4a-5b)-a(6a+4b)=
A (3a+2b)(2a5b)(3a+2b)(2a-5b).
B (3a+2b)(6a5b)(3a+2b)(6a-5b).
C (3a2b)(2a+5b)(3a-2b)(2a+5b).
D (3a2b)(6a+5b)(3a-2b)(6a+5b).
2020 · Paper 2 Q5 Functions and graphs
Let f(x)=3x2x2f(x)=3x^{2}-x-2. If β\beta is a constant, then f(1+β)f(1β)=f(1+\beta)-f(1-\beta)=
A 2β2\beta.
B 10β10\beta.
C 6β226\beta^{2}-2.
D 6β22β6\beta^{2}-2\beta.
2020 · Paper 2 Q6 More about polynomials
Let g(x)=ax3+4ax224g(x)=ax^{3}+4ax^{2}-24, where a is a constant. If x+2x+2 is a factor of g(x)g(x), then g(2)=g(2)=
A 0.
B 0.
C 0.
D 48.
2020 · Paper 2 Q7 Identities
If hh and kk are constants such that (x+h)(x+6)(x+4)2+k(x+h)(x+6) \equiv (x+4)^{2}+k, then k=k =
A -28.
B -16.
C -4.
D 2.
2020 · Paper 2 Q8 Equations of straight lines
In the figure, the equations of the straight lines L1L_{1} and L2L_{2} are x+ay+b=0x + ay + b = 0 and bx+y+c=0bx + y + c = 0 respectively. Which of the following are true?

I. c<0c < 0
II. ab<1ab < 1
III. ac<bac < b
Figure
A I and II only
B I and III only
C II and III only
D I, II and III
2020 · Paper 2 Q9 Using percentages
The cost of a toy is x%x\% lower than its selling price. After selling the toy, the percentage profit is 25%25\%. Find xx.
A 2020
B 2525
C 7575
D 8080
2020 · Paper 2 Q10 Rates, ratios and proportions
The actual area of a golf course is 0.75 km20.75\text{ km}^{2}. If the area of the course on a map is 100 cm2100\text{ cm}^{2}, then the scale of the map is
A 1:2501:250.
B 1:50001:5000.
C 1:625001:62500.
D 1:250000001:25000000.
2020 · Paper 2 Q11 Variations
It is given that ww varies as the cube of uu and the square root of vv. When u=2u=2 and v=4v=4, w=8w=8. When u=4u=4 and v=9v=9, w=w=
A 9696.
B 324324.
C 384384.
D 729729.
2020 · Paper 2 Q12 Arithmetic and geometric sequences and their summations
In the figure, the 1st pattern consists of 3 dots. For any positive integer nn, the (n+1)(n+1)th pattern is formed by adding (2n+1)(2n+1) dots to the nnth pattern. Find the number of dots in the 7th pattern.
Figure
A 1515.
B 2727.
C 3838.
D 5151.
2020 · Paper 2 Q13 Inequalities and linear programming
The solution of 54x<95-4x<9 and 2x37>1\frac{2x-3}{7}>1 is
A x<1x<-1.
B x>1x>-1.
C x<5x<5.
D x>5x>5.
2020 · Paper 2 Q14 Errors in measurement
In the figure, PQRSTP_{QRST} is a pentagon, where all the measurements are correct to the nearest cm. Let A cm2A \text{ cm}^2 be the actual area of the pentagon. Find the range of values of AA.
Figure
A 27.83qA<31.8327.83 \le q A < 31.83.
B 44.75qA<60.7544.75 \le q A < 60.75.
C 46.75qA<63.2546.75 \le q A < 63.25.
D 48.25qA<64.7548.25 \le q A < 64.75.
2020 · Paper 2 Q15 Arc lengths and areas of sectors
The angle of a sector is decreased by 60%60\% but its radius is increased by k%k\%. If the arc length of the sector remains unchanged, find the value of kk.
A 4040.
B 6060.
C 6767.
D 150150.
2020 · Paper 2 Q16 Mensuration
If the volume of a right circular cylinder of base radius 5a cm5a\text{ cm} and height 7b cm7b\text{ cm} is 525 cm3525\text{ cm}^{3}, then the volume of a right circular cone of base radius 7a cm7a\text{ cm} and height 5b cm5b\text{ cm} is
A 175 cm3175\text{ cm}^{3}
B 245 cm3245\text{ cm}^{3}
C 490 cm3490\text{ cm}^{3}
D 735 cm3735\text{ cm}^{3}
2020 · Paper 2 Q17 Similar triangles
In the figure, P and Q are points lying on OR while U and T are points lying on OS such that OP=PQ=QROP = PQ = QR and PUQTRSPU \parallel QT \parallel RS. The ratio of the area of the trapezium QRSTQRST is
Figure
2020 · Paper 2 Q18 Similar triangles
In the figure, ABCDABCD is a parallelogram. Let EE be a point lying on ADAD such that AE:ED=2:5AE:ED=2:5. CBCB is produced to the point FF such that BF=DEBF=DE. Denote the point of intersection of ABAB and EFEF by GG. It is given that BDBD and CGCG intersect at the point HH. If the area of AEG\triangle AEG is 48 cm248\mathrm{~cm}^{2}, then the area of CDH\triangle CDH is
Figure
A 98 cm298\text{ cm}^{2}
B 343 cm2343\text{ cm}^{2}
C 420 cm2420\text{ cm}^{2}
D 588 cm2588\text{ cm}^{2}
2020 · Paper 2 Q19 Angles and parallel lines
According to the figure, which of the following must be true?

I. uv+w=0u - v + w = 0^{\circ}

II. u+vw=180u + v - w = 180^{\circ}

III. u+v+w=450u + v + w = 450^{\circ}
Figure
A I only.
B II only.
C I and III only.
D II and III only.
2020 · Paper 2 Q20 Polygons
In the figure, ABCABC is an equilateral triangle and CDECDE is an isosceles triangle with CD=CECD = CE. If DCE=78\angle DCE = 78^{\circ} and ADC=CAD=40\angle ADC = \angle CAD = 40^{\circ}, then CBE=\angle CBE =
Figure
A 1414^{\circ}.
B 1919^{\circ}.
C 2424^{\circ}.
D 2929^{\circ}.
2020 · Paper 2 Q21 Pythagoras' theorem
In the figure, ABCDABCD is a rectangle. Let EE be a point lying on ADAD such that BE=8 cmBE = 8\ \text{cm} and CE=15 cmCE = 15\ \text{cm}. If BC=17 cmBC = 17\ \text{cm}, find the area of the rectangle ABCDABCD.
Figure
A 60 cm260\ cm^{2}.
B 68 cm268\ cm^{2}.
C 120 cm2120\ cm^{2}.
D 136 cm2136\ cm^{2}.
2020 · Paper 2 Q22 Basic properties of circles
In the figure, ABCDEABCDE is a circle. If AB=10 cmAB=10\text{ cm}, BC=5 cmBC=5\text{ cm}, ABC=90\angle ABC=90^{\circ} and CED=40\angle CED=40^{\circ} find CDCD correct to the nearest cm\text{cm}.
Figure
A 5 cm5\text{ cm}.
B 6 cm6\text{ cm}.
C 7 cm7\text{ cm}.
D 8 cm8\text{ cm}.
2020 · Paper 2 Q23 Trigonometry
A ship is 50 km50\text{ km} due west of a lighthouse. If the ship moves in the direction S60ES60^{\circ}E, find the shortest distance between the ship and the lighthouse.
A 20 km20\text{ km}.
B 25 km25\text{ km}.
C 43 km43\text{ km}.
D 87 km87\text{ km}.
2020 · Paper 2 Q24 Rectangular coordinate system
The point PP is translated leftwards by 4 units to the point QQ. If the coordinates of the reflection image of QQ with respect to the yy-axis are (5,1)(5,-1), then the polar coordinates of PP are
A (1,45)(1,45^{\circ}).
B (1,225)(1,225^{\circ}).
C (2,45)(\sqrt{2},45^{\circ}).
D (2,225)(\sqrt{2},225^{\circ}).
2020 · Paper 2 Q25 Loci
Let AA be the point of intersection of the straight lines 9x+4y7=09x+4y-7=0 and 9x4y+7=09x-4y+7=0. If PP is a moving point in the rectangular coordinate plane such that the distance between PP and AA is 88, then the locus of PP is a
A circle.
B triangle.
C quadrilateral.
D regular hexagon.
2020 · Paper 2 Q26 Equations of straight lines
The equation of the straight line LL is kx+4y2k=0kx+4y-2k=0, where kk is a constant. If LL is perpendicular to the straight line 6x9y+4=06x-9y+4=0, find the yy-intercept of LL.
A 3-3
B 2-2
C 22
D 33
2020 · Paper 2 Q27 Equations of circles
The equations of the circles C1C_{1} and C2C_{2} are 2x2+2y2+4x+8y149=02x^{2}+2y^{2}+4x+8y-149=0 and x2+y28x20y53=0x^{2}+y^{2}-8x-20y-53=0 respectively. Which of the following is/are true?
I. The centre of C1C_{1} lies on C2C_{2}.
II. The radii of C1C_{1} and C2C_{2} are equal.
III. C1C_{1} and C2C_{2} intersect at two distinct points.
A I only
B II only
C I and III only
D II and III only
2020 · Paper 2 Q28 Probability
Two numbers are randomly drawn at the same time from four cards numbered 3, 5, 7 and 9 respectively. Find the probability that the product of the numbers drawn is greater than 3535.
A 12\frac{1}{2}
B 13\frac{1}{3}
C 23\frac{2}{3}
D 38\frac{3}{8}
2020 · Paper 2 Q29 Measures of dispersion
The bar chart below shows the distribution of the numbers of pens owned by some students. Find the inter-quartile range of the distribution.
Figure
A 11
B 22
C 44
D 66
2020 · Paper 2 Q30 Measures of dispersion
Consider the following integers:

33 33 88 88 1010 1212 mm nn

Let xx, yy and zz be the median, the mean and the mode of the above integers respectively. If the range of the above integers is 99, which of the following must be true?

I. x=8x=8

II. y=8y=8

III. z=8z=8
A I only
B II only
C I and III only
D II and III only
2020 · Paper 2 Q31 Exponential and logarithmic functions
B000000000000030_{16} =
A 10×260+4810 \times 2^{60} + 48
B 11×260+4811 \times 2^{60} + 48
C 10×264+76810 \times 2^{64} + 768
D 11×264+76811 \times 2^{64} + 768