DSE Mathematics · Core

Past paper questions

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

Topic
990 questions
2012 · Paper 2 Q32 Exponential and logarithmic functions
The graph in the figure shows the linear relation between xx and log3y\log_{3} y. If y=mnxy = mn^{x}, then n=n =
Figure
A 181\frac{1}{81}.
B 19\frac{1}{9}.
C 99.
D 8181.
2012 · Paper 2 Q33 Basic computation
AD000000201216=_{16} =
A (10)1611+(13)1610+8210(10)16^{11} + (13)16^{10} + 8210
B (10)1612+(13)1611+131360(10)16^{12} + (13)16^{11} + 131360
C (11)1611+(14)1610+8210(11)16^{11} + (14)16^{10} + 8210
D (11)1612+(14)1611+131360(11)16^{12} + (14)16^{11} + 131360
2012 · Paper 2 Q34 Quadratic equations in one unknown
Let f(x)f(x) be a quadratic function. If the coordinates of the vertex of the graph of y=f(x)y = f(x) are (3,4)(3, -4), which of the following must be true?
A The roots of the equation f(x)=0f(x) = 0 are integers.
B The roots of the equation f(x)3=0f(x)-3=0 are rational numbers.
C The roots of the equation f(x)+4=0f(x)+4=0 are real numbers.
D The roots of the equation f(x)+5=0f(x)+5=0 are non-real numbers.
2012 · Paper 2 Q35 Laws of integral indices
i3(βi3)=i^{3}(\beta i-3)=
A β+3i\beta+3i
B β3i\beta-3i
C β+3i-\beta+3i
D β3i-\beta-3i
2012 · Paper 2 Q36 Inequalities and linear programming
The figure shows a shaded region (including the boundary). If (h,k)(h, k) is a point lying in the shaded region, 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
2012 · Paper 2 Q37 Arithmetic and geometric sequences and their summations
Let ana_{n} be the nnth term of an arithmetic sequence. If a18=26a_{18}=26 and a23=61a_{23}=61, 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
2012 · Paper 2 Q38 More about graphs of functions
Which of the following may represent the graph of y=f(x)y = f(x) and the graph of y=f(x2)+1y = f(x - 2) + 1 on the same rectangular coordinate system?
A
B
C
D
2012 · Paper 2 Q39 More about trigonometry
The figure shows
A the graph of y=1+3cosx2y=1+3\cos\frac{x^{\circ}}{2}.
B the graph of y=1+3cos2xy=1+3\cos 2x^{\circ}.
C the graph of y=4+3cosx2y=4+3\cos\frac{x^{\circ}}{2}.
D the graph of y=4+3cos2xy=4+3\cos 2x^{\circ}.
2012 · Paper 2 Q40 3-D figures
The figure shows a regular tetrahedron ABCDABCD. Find the angle between the plane ABCABC and the plane BCDBCD correct to the nearest degree.
Figure
A 4848^{\circ}
B 5353^{\circ}
C 6060^{\circ}
D 7171^{\circ}
2012 · Paper 2 Q41 Basic properties of circles
In the figure, PQPQ is the tangent to the circle ABCABC at OO, where OO is the centre of the semicircle PBQPBQ. It is given that BCPBCP is a straight line. If BPQ=12\angle BPQ = 12^{\circ}, then BAC=\angle BAC =
Figure
A 1818^{\circ}
B 2424^{\circ}
C 3636^{\circ}
D 5454^{\circ}
2012 · Paper 2 Q42 Equations of circles
Find the range of values of kk such that the circle x2+y2+2x4y13=0x^{2}+y^{2}+2x-4y-13=0 and the straight line xy+k=0x-y+k=0 intersect at two distinct points.
A 9<k<3-9 < k < 3
B 3<k<9-3 < k < 9
C k<9k < -9 or k>3k > 3
D k<3k < -3 or k>9k > 9
2012 · Paper 2 Q43 Permutations and combinations
A drama club is formed by 12 boys and 8 girls. If a team of 5 students is selected from the club to participate in a competition and the team consists of at least one girl, how many different teams can be formed?
A 39603960
B 1471214712
C 1544815448
D 1550415504
2012 · Paper 2 Q44 More about probability
A box contains six balls numbered 7, 8, 9, 9 and 9 respectively. John repeats drawing one ball at a time randomly from the box without replacement until the number drawn is 9. Find the probability that he needs exactly three draws.
A 12\frac{1}{2}
B 16\frac{1}{6}
C 18\frac{1}{8}
D 320\frac{3}{20}
2012 · Paper 2 Q45 Measures of dispersion
Let m1m_{1}, r1r_{1} and v1v_{1} be the mean, the range and the variance of a group of numbers {x1,x2,x3,,x100}\{x_{1}, x_{2}, x_{3}, \ldots, x_{100}\} respectively. If m2m_{2}, r2r_{2} and v2v_{2} are the mean, the range and the variance of the group of numbers {x1,x2,x3,,x100,m1}\{x_{1}, x_{2}, x_{3}, \ldots, x_{100}, m_{1}\} respectively, which of the following must be true?

I. m1=m2m_{1}=m_{2}

II. r1=r2r_{1}=r_{2}

III. v1=v2v_{1}=v_{2}
A I and II only
B I and III only
C II and III only
D I, II and III
2013 · Paper 1 Q1 Laws of integral indices
Simplify x20y13(x5y)6\frac{x^{20}y^{13}}{(x^{5}y)^{6}} and express your answer with positive indices. (3 marks)
2013 · Paper 1 Q2 Formulae
Make kk the subject of the formula 3h1k=2\frac{3}{h}-\frac{1}{k}=2. (3 marks)
2013 · Paper 1 Q3 Identities
(a) Factorize 4m225n24m^{2}-25n^{2}
(b) 4m225n2+6m15n4m^{2}-25n^{2}+6m-15n (3 marks)
2013 · Paper 1 Q4 Linear equations in two unknowns
The price of 7 pears and 3 oranges is 47whilethepriceof5pearsand6orangesis47 while the price of 5 pears and 6 oranges is 49. Find the price of a pear. (4 marks)
2013 · Paper 1 Q5 Inequalities and linear programming
(a) Solve the inequality 197x3>235x \frac{19-7x}{3}>23-5x
(b) Find all integers satisfying both the inequalities 197x3>235x \frac{19-7x}{3}>23-5x and 182x0 18-2x\geq 0 .
2013 · Paper 1 Q6 Trigonometry
In a polar coordinate system, OO is the pole. The polar coordinates of the points AA and BB are (26,10)(26,10^{\circ}) and (26,130)(26,130^{\circ}) respectively. Let LL be the axis of reflectional symmetry of ΔOAB\Delta OAB.
(a) Describe the geometric relationship between LL and AOB \angle AOB .
(b) Find the polar coordinates of the point of intersection of LL and ABAB. (4 marks)
2013 · Paper 1 Q7 Congruent triangles
In Figure 1, ABCDABCD is a quadrilateral. The diagonals ACAC and BDBD intersect at EE. It is given that BE=CEBE = CE and BAC=BDC\angle BAC = \angle BDC.
Figure
(a) Prove that ΔABCΔDCB\Delta ABC \cong \Delta DCB.
(b) Consider the triangles in Figure 1.
(i) How many pairs of congruent triangles are there?
(ii) How many pairs of similar triangles are there? (4 marks)
2013 · Paper 1 Q8 Errors in measurement
A pack of sea salt is termed regular if its weight is measured as 100 g100\text{ g} correct to the nearest g.
(a) Find the least possible weight of a regular pack of sea salt.
(b) Is it possible that the total weight of 3232 regular packs of sea salt is measured as 3.1 kg3.1\text{ kg} correct to the nearest 0.1 kg0.1\text{ kg} ? Explain your answer. (5 marks)
2013 · Paper 1 Q9 Measures of dispersion
The bar chart below shows the distribution of the numbers of family members of the employees of company DD.
Figure
(a) Find the mean, the inter-quartile range and the standard deviation of the above distribution.
(b) An employee leaves company DD. The number of family members of this employee is 77. Find the change in the standard deviation of the numbers of family members of the employees of company DD due to the leaving of this employee. (5 marks)
2013 · Paper 1 Q10 Measures of dispersion
The ages of the members of Committee A are shown as follows:
(a) Write down the median and the mode of the ages of the members of Committee A. (2 marks)
(b) The stem-and-leaf diagram below shows the distribution of the ages of the members of Committee B. It is given that the range of this distribution is 4747.
(i) Find aa and bb.
(ii) From each committee, a member is randomly selected as the representative of that committee. The two representatives can join a competition when the difference of their ages exceeds 4040. Find the probability that these two representatives can join the competition. (4 marks)
2013 · Paper 1 Q11 Variations
The weight of a tray of perimeter \ell metres is WW grams. It is given that WW is the sum of two parts, one part varies directly as \ell and the other part varies directly as 2\ell^{2}. When =1\ell=1, W=181W=181 and when =2\ell=2, W=402W=402.
(a) Find the weight of a tray of perimeter 1.2 metres. (4 marks)
(b) If the weight of a tray is 594 grams, find the perimeter of the tray. (2 marks)
2013 · Paper 1 Q12 More about polynomials
Let f(x)=3x37x2+kx8f(x)=3x^{3}-7x^{2}+kx-8, where kk is a constant. It is given that f(x)(x2)(ax2+bx+c)f(x)\equiv(x-2)(ax^{2}+bx+c), where aa, bb and cc are constants.
(a) Find aa, bb and cc.
(b) Someone claims that all the roots of the equation f(x)=0f(x)=0 are real numbers. Do you agree? Explain your answer. (3 marks)
2013 · Paper 1 Q13 Mensuration
In a workshop, 2 identical solid metal right circular cylinders of base radius RR cm are melted and recast into 27 smaller identical solid right circular cylinders of base radius rr cm and height 1010 cm. It is given that the base area of a larger circular cylinder is 9 times that of a smaller one.
(a) Find
(i) r:Rr:R,
(ii) the height of a larger circular cylinder.
(b) A craftsman claims that a smaller circular cylinder and a larger circular cylinder are similar. Do you agree? Explain your answer. (2 marks)
2013 · Paper 1 Q14 Equations of circles
The equation of the circle CC is x2+y212x34y+225=0x^{2}+y^{2}-12x-34y+225=0. Denote the centre of CC by RR.
(a) Write down the coordinates of RR. (1 mark)
(b) The equation of the straight line LL is 4x+3y+50=04x + 3y + 50 = 0. It is found that CC and LL do not intersect. Let PP be a point lying on LL such that PP is nearest to RR.
(i) Find the distance between PP and RR.
(ii) Let QQ be a moving point on CC. When QQ is nearest to PP,
2013 · Paper 1 Q15 Measures of dispersion
The box-and-whisker diagram below shows the distribution of the scores (in marks) of the students of a class in a test. Susan gets the highest score while Tom gets 6565 marks in the test. The standard scores of Susan and Tom in the test are 33 and 0.50.5 respectively.
Figure
(a) Find the mean of the distribution.
(b) Susan claims that the standard scores of at least half of the students in the test are negative. Do you agree? Explain your answer. (2 marks)
2013 · Paper 1 Q16 Probability
A box contains 5 white cups and 11 blue cups. If 6 cups are randomly drawn from the box at the same time,
(a) find the probability that at least 44 white cups are drawn; (2 marks)
(b) find the probability that at least 33 blue cups are drawn. (2 marks)
2013 · Paper 1 Q17 Quadratic equations in one unknown
(a) Let f(x)=36xx2f(x)=36x-x^{2}. Using the method of completing the square, find the coordinates of the vertex of the graph of y=f(x)y=f(x). (2 marks)
(b) The length of a piece of string is 108 m108\text{ m}. A guard cuts the string into two pieces. One piece is used to enclose a rectangular restricted zone of area A m2A\text{ m}^{2}. The other piece of length x mx\text{ m} is used to divide this restricted zone into two rectangular regions as shown in Figure 2.
Figure
(i) Express AA in terms of xx.
(ii) The guard claims that the area of this restricted zone can be greater than 500 m2500\text{ m}^{2}. Do you agree? Explain your answer.
2013 · Paper 1 Q18 Trigonometry
(a) Figure 3(a) shows a piece of triangular paper card ABCABC with AB=28 cmAB=28\text{ cm}, BC=21 cmBC=21\text{ cm} and AC=35 cmAC=35\text{ cm}. Let MM be a point lying on ACAC such that BMC=75\angle BMC=75^{\circ}.

Find
Figure
(i) BCM\angle BCM.
(ii) CMCM.
(3 marks)
(b) Peter folds the triangular paper card described in (a) along BMBM such that ABAB and BCBC lie on the horizontal ground as shown in Figure 3(b). It is given that AMC=107\angle AMC = 107^{\circ}.
Figure
(i) Find the distance between AA and CC on the horizontal ground.
(ii) Let NN be a point lying on BCBC such that MNMN is perpendicular to BCBC. Peter claims that the angle between the face BCMBCM and the horizontal ground is ANM\angle ANM. Do you agree? Explain your answer.
2013 · Paper 1 Q19 Arithmetic and geometric sequences and their summations
The development of public housing in a city is under study. It is given that the total floor area of all public housing flats at the end of the 1st year is 9×106 m29 \times 10^6 \text{ m}^2 and in subsequent years, the total floor area of public housing flats built each year is r%r\% of the total floor area of all public housing flats at the end of the previous year, where rr is a constant, and the total floor area of public housing flats pulled down each year is 3×105 m23 \times 10^5 \text{ m}^2. It is found that the total floor area of all public housing flats at the end of the 3rd year is 1.026×107 m21.026 \times 10^7 \text{ m}^2.
(a)
(i) Express, in terms of rr, the total floor area of all public housing flats at the end of the 2nd year.
(ii) Find rr.
(b)
(i) Express, in terms of nn, the total floor area of all public housing flats at the end of the nthn^{th} year.
(ii) At the end of which year will the total floor area of all public housing flats first exceed 4×107 m24 \times 10^{7} \text{ m}^{2}?

(5 marks)
(c) It is assumed that the total floor area of public housing flats needed at the end of the nnth year is (a(1.21)n+b) m2(a(1.21)^n + b)\text{ m}^2, where aa and bb are constants. Some research results reveal the following information:

[Table]

A research assistant claims that based on the above assumption, the total floor area of all public housing flats will be greater than the total floor area of public housing flats needed at the end of a certain year. Is the claim correct? Explain your answer. (4 marks)
2013 · Paper 2 Q1 Laws of integral indices
(279n+1)3= (27 \cdot 9^{n+1})^3 =
A 36n+12 3^{6n+12}
B 36n+15 3^{6n+15}
C 39n+12 3^{9n+12}
D 39n+18 3^{9n+18}
2013 · Paper 2 Q2 Formulae
If y1c=y+1d \frac{y-1}{c}=\frac{y+1}{d} , then y=
A cdc+d \frac{c-d}{c+d}
B dcc+d \frac{d-c}{c+d}
C c+dcd \frac{c+d}{c-d}
D c+ddc \frac{c+d}{d-c}
2013 · Paper 2 Q3 Polynomials
hk+hmkmhn+kn= h\ell - k\ell + hm - km - hn + kn =
A (h+k)(m+n) (h+k)(\ell-m+n)
B (h+k)(+mn) (h+k)(\ell+m-n)
C (hk)(m+n) (h-k)(\ell-m+n)
D (hk)(+mn) (h-k)(\ell+m-n)
2013 · Paper 2 Q4 Approximate values and numerical estimation
0.0504545=0.0504545 =
A 0.0510.051 (correct to 2 significant figures).
B 0.05050.0505 (correct to 3 decimal places).
C 0.050450.05045 (correct to 4 significant figures).
D 0.050460.05046 (correct to 5 decimal places).
2013 · Paper 2 Q5 Inequalities and linear programming
The solution of xx12>5x - \frac{x-1}{2} > 5 or 1<x111 < x - 11 is
A x>9x > 9.
B x>10x > 10.
C x>11x > 11.
D x>12x > 12.
2013 · Paper 2 Q6 Quadratic equations in one unknown
Let kk be a constant. Solve the equation (xk)2=4k2(x-k)^{2}=4k^{2}.
A x=3kx = 3k
B x=5kx = 5k
C x=kx = -k or x=3kx = 3k
D x=3kx = -3k or x=5kx = 5k
2013 · Paper 2 Q7 Functions and graphs
The figure shows the graph of y=2x2+ax+by = -2x^{2} + ax + b, where aa and bb are constants. The equation of the axis of symmetry of the graph is
Figure
A x=2x = 2.
B x=3x = 3.
C x=5x = 5.
D y=8y = 8.
2013 · Paper 2 Q8 Identities
If aa, bb and cc are non-zero constants such that x(x+3a)+ax2+2(bx+c)x(x+3a)+a \equiv x^{2}+2(bx+c), then a:b:c=a:b:c=
A 2:3:12:3:1.
B 2:3:42:3:4.
C 3:2:63:2:6.
D 6:4:36:4:3.
2013 · Paper 2 Q9 More about polynomials
Let f(x)=x132x+kf(x)=x^{13}-2x+k, where kk is a constant. If f(x)f(x) is divisible by x+1x+1, find the remainder when f(x)f(x) is divided by x1x-1.
A 0
B 1-1
C 2
D 2-2
2013 · Paper 2 Q10 Using percentages
Susan sells two cars for \80\,080each.Shegains each. She gains 30\%ononeandloses on one and loses 30\%$ on the other. After the two transactions, Susan
A loses \15\,840$.
B gains \5\,544$.
C gains \10\,296$.
D has no gain and no loss.
2013 · Paper 2 Q11 Using percentages
A sum of \50\,000isdepositedataninterestrateof is deposited at an interest rate of 8\%$ per annum for 1 year, compounded monthly. Find the interest correct to the nearest dollar.
A \4000$
B \4122$
C \4143$
D \4150$
2013 · Paper 2 Q12 Rates, ratios and proportions
The actual area of a playground is 900extm2900 ext{ m}^{2}. If the area of the playground on a map is 36extcm236 ext{ cm}^{2}, then the scale of the map is
A 1:251:25.
B 1:501:50.
C 1:5001:500.
D 1:250 0001:250\ 000.
2013 · Paper 2 Q13 Variations
It is given that zz varies directly as xx and inversely as y\sqrt{y}. If yy is decreased by 64%64\% and zz is increased by 25%25\%, then xx
A is increased by 20%20\%.
B is increased by 80%80\%.
C is decreased by 25%25\%.
D is decreased by 75%75\%.
2013 · Paper 2 Q14 Equations of straight lines
The figure shows the graph of the straight line x+ay+b=0x + ay + b = 0. Which of the following are true?

I. a<0a < 0

II. b<0b < 0

III. a<ba < b
Figure
A I and II only
B I and III only
C II and III only
D I, II and III
2013 · Paper 2 Q15 Polygons
In the figure, the regular octagon is divided into eight identical isosceles triangles and four of the shaded. The number of axes of reflectional symmetry of the octagon is
Figure
A 22.
B 44.
C 88.
D 1616.
2013 · Paper 2 Q16 Arc lengths and areas of sectors
In the figure, the diameter of the semicircle ABCABC is 3 cm 3\text{ cm }. If AC=2AC = 2 cm, find the area of the shaded region correct to the nearest 0.010.01 cm2^2.
Figure
A 0.23 cm20.23\text{ cm}^{2}.
B 0.52 cm20.52\text{ cm}^{2}.
C 0.64 cm20.64\text{ cm}^{2}.
D 1.07 cm21.07\text{ cm}^{2}.
2013 · Paper 2 Q17 Mensuration
In the figure, the solid consists of a right circular cone and a hemisphere with a common base. The base radius and the height of the circular cone are 3 cm 3\text{ cm } and 4 cm 4\text{ cm } respectively. Find the total surface area of the solid.
Figure
A 30π cm230\pi\text{ cm}^{2}.
B 33π cm233\pi\text{ cm}^{2}.
C 48π cm248\pi\text{ cm}^{2}.
D 51π cm251\pi\text{ cm}^{2}.