DSE Mathematics · Core

Past paper questions

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

Topic
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2016 · Paper 1 Q2 Formulae
(a) Make xx the subject of the formula Ax=(4x+B)CAx = (4x + B)C. (3 marks)
2016 · Paper 1 Q3 Polynomials
() Simplify 24x5+316x\frac{2}{4x-5}+\frac{3}{1-6x}. (3 marks)
2016 · Paper 1 Q4 Polynomials
(a) 5m10n5m-10n
(b) m2+mn6n2m^{2}+mn-6n^{2}
(c) m2+mn6n25m+10nm^{2}+mn-6n^{2}-5m+10n (4 marks)
2016 · Paper 1 Q5 Using percentages
In a recreation club, there are 180 members and the number of male members is 40%40\% more than the number of female members. Find the difference of the number of male members and the number of female members. (4 marks)
2016 · Paper 1 Q6 Linear inequalities in one unknown
(a) Solve ()(*).
(b) Write down the greatest negative integer satisfying ()(*). (4 marks)
2016 · Paper 1 Q7 Basic properties of circles
(a) Find AOB \angle AOB .
(b) Find the perimeter of ΔAOB \Delta AOB .
(c) Write down the number of folds of rotational symmetry of ΔAOB \Delta AOB . (4 marks)
2016 · Paper 1 Q8 Variations
It is given that f(x) f(x) is the sum of two parts, one part varies as xx and the other part varies as x2 x^{2} . Suppose that f(3)=48 f(3)=48 and f(9)=198 f(9)=198 .
(a) Find f(x) f(x) .
(b) Solve the equation f(x)=90 f(x)=90
2016 · Paper 1 Q9 Organisation of data
The frequency distribution table and the cumulative frequency distribution table below show the distribution of the heights of the plants in a garden.
(a) Find xx, yy and zz.
(b) If a plant is randomly selected from the garden, find the probability that the height of the selected plant is less than 1.25 m1.25\text{ m} but not less than 0.65 m0.65\text{ m}.
(5 marks)
2016 · Paper 1 Q10 Equations of circles
(a) Find the equation of Γ\Gamma.

(2 marks)
(b) Γ\Gamma intersects the xx-axis and the yy-axis at HH and KK respectively. Denote the origin by OO. Let CC be the circle which passes through OO, HH and KK. Someone claims that the circumference of CC exceeds 3030. Is the claim correct? Explain your answer.
(3 marks)
2016 · Paper 1 Q11 Mensuration
An inverted right circular conical vessel contains some milk. The vessel is held vertically. The depth of milk in the vessel is 12 cm 12\text{ cm }. Peter then pours 444π444\pi cm^{3} of milk into the vessel without overflowing. He now finds that the depth of milk in the vessel is 16 cm 16\text{ cm }.
(a) Express the final volume of milk in the vessel in terms of π\pi. (3 marks)
(b) Peter claims that the final area of the wet curved surface of the vessel is at least 800800 cm^{2}. Do you agree? Explain your answer. (3 marks)
2016 · Paper 1 Q12 Measures of dispersion
Figure
(a) Find aa and bb.
(b) Four more children now join the group. It is found that the ages of these four children are all different and the range of the ages of the children in the group remains unchanged. Find
(i) the greatest possible median of the ages of the children in the group,
(ii) the least possible mean of the ages of the children in the group. ( ) Aqv 22d
2016 · Paper 1 Q13 Congruent triangles
Figure
(a) Prove that ΔACDΔABE\Delta ACD \cong \Delta ABE.
(b) Suppose that AD=15 cmAD=15\text{ cm}, BD=7 cmBD=7\text{ cm} and DE=18 cmDE=18\text{ cm}.
(i) Find AMAM.
(ii) Is ΔABE\Delta ABE a right-angled triangle? Explain your answer. (5 marks)
2016 · Paper 1 Q14 More about polynomials
(a) Find ll, mm and nn.
(b) How many real roots does the equation p(x)=0p(x) = 0 have? Explain your answer. (5 marks)
2016 · Paper 1 Q15 Permutations and combinations
If 44 boys and 55 girls randomly form a queue, find the probability that no boys are next to each other in the queue. (3 marks)
2016 · Paper 1 Q16 Measures of dispersion
In a test, the mean of the distribution of the scores of a class of students is 6161 marks. The standard scores of Albert and Mary are 2.6-2.6 and 1.41.4 respectively. Albert gets 2222 marks. A student claims that the range of the distribution is at most 5959 marks. Is the claim correct? Explain your answer.
2016 · Paper 1 Q17 Arithmetic and geometric sequences and their summations
The 1st term and the 38th term of an arithmetic sequence are 666666 and 555555 respectively. Find
(a) the common difference of the sequence, (2 marks)
(b) the greatest value of nn such that the sum of the first nn terms of the sequence is positive. (3 marks)
2016 · Paper 1 Q18 Quadratic equations in one unknown
(a) 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 graph of y=g(x)y = g(x) is obtained by translating the graph of y=f(x)y = f(x) vertically. If the graph of y=g(x)y = g(x) touches the xx-axis, find g(x)g(x). (2 marks)
(c) Under a transformation, f(x)f(x) is changed to 13x212x121\frac{-1}{3}x^2 - 12x - 121. Describe the geometric meaning of the transformation. (2 marks)
2016 · Paper 1 Q19 3-D figures
Figure 2 shows a geometric model ABCDABCD in the form of tetrahedron. It is given that BAD=86\angle BAD = 86^{\circ}, CBD=43\angle CBD = 43^{\circ}, AB=10AB = 10 cm, AC=6AC = 6 cm, BC=8BC = 8 cm and BD=15BD = 15 cm.
Figure
(a) Find ABD\angle ABD and CDCD.
(b) A craftsman claims that the angle between ABAB and the face BCDBCD is ABC\angle ABC. Do you agree? Explain your answer. (2 marks)
2016 · Paper 1 Q20 Equations of circles
(a) Prove that OP=PQOP = PQ.
(b) A rectangular coordinate system is introduced so that the coordinates of OO and QQ are (0,0)(0,0) and (40,30)(40,30) respectively while the yy-coordinate of PP is 1919. Let CC be the circle which passes through OO, PP and QQ.
(i) Find the equation of CC.
(ii) Let L1L_{1} and L2L_{2} be two tangents to CC such that the slope of each tangent is 34\frac{3}{4} and the yy-intercept of L1L_{1} is greater than that of L2L_{2}. L1L_{1} cuts the xx-axis and the yy-axis at SS and TT respectively while L2L_{2} cuts the xx-axis and the yy-axis at UU and VV respectively. Someone claims that the area of the trapezium STUVSTUV exceeds 1700017000. Is the claim correct? Explain your answer.
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)
Sample paper · Paper 1 Q1 Laws of integral indices
Simplify (xy)2x5y6 \frac{(xy)^2}{x^{-5}y^6} and express your answer with positive indices.
Sample paper · Paper 1 Q2 Formulae
Make bb the subject of the formula a(b+7)=a+b a(b+7)=a+b
Sample paper · Paper 1 Q3 Polynomials
Factorize
(a) 3m2mn2n2,3m^{2}-m n-2n^{2},
(b) 3m2mn2n2m+n.3m^{2}-m n-2n^{2}-m+n. (3 marks)
Sample paper · Paper 1 Q4 Using percentages
The marked price of a handbag is \560.Itisgiventhatthemarkedpriceofthehandbagis. It is given that the marked price of the handbag is 40\%$ higher than the cost.
(a) Find the cost of the handbag.
(b) If the handbag is sold at \460$, find the percentage profit. (4 marks)
Sample paper · Paper 1 Q5 Linear equations in two unknowns
In a football league, each team gains 3 points for a win, 1 point for a draw and 0 point for a loss. The champion of the league plays 36 games and gains a total of 84 points. Given that the champion does not lose any games, find the number of games that the champion wins.
Sample paper · Paper 1 Q6 Mensuration
Figure
(a) Find rr.
(b) Express the volume of the solid in terms of π\pi. (4 marks)
Sample paper · Paper 1 Q7 Basic properties of circles
In Figure 2, OO is the centre of the semicircle ABCDABCD. If ABOCAB \parallel OC and BAD=38\angle BAD = 38^{\circ}, find BDC\angle BDC.
Figure
Sample paper · Paper 1 Q8 Rectangular coordinate system
In Figure 3, the coordinates of the point AA are (2,5)(-2,5). AA is rotated clockwise about the origin OO through 9090^{\circ} to AA'. AA'' is the reflection image of AA with respect to the yy-axis.
Figure
(a) Write down the coordinates of AA' and AA''.
(b) Is OAOA'' perpendicular to AAAA' ? Explain your answer.
Sample paper · Paper 1 Q9 Presentation of data
Figure
(a) Find xx.
(b) Is the number of traffic accidents occurred in District A greater than that in District C? Explain your answer. (5 marks)
Sample paper · Paper 1 Q10 More about polynomials
(a) Find the quotient when 5x3+12x29x75x^{3}+12x^{2}-9x-7 is divided by x2+2x3x^{2}+2x-3.
(b) Let g(x)=(5x3+12x29x7)(ax+b)g(x)=(5x^{3}+12x^{2}-9x-7)-(ax+b), where aa and bb are constants. It is given that g(x)g(x) is divisible by x2+2x3x^{2}+2x-3.
(i) Write down the values of aa and bb.
(ii) Solve the equation g(x)=0g(x)=0 (4 marks)
Sample paper · Paper 1 Q11 Variations
In a factory, the production cost of a carpet of perimeter ss metres is CC. It is given that CC is a sum of two parts, one part varies as ss and the other part varies as the square of ss. When s=2s=2, C=356C=356; when s=5s=5, C=1250C=1250.
(a) Find the production cost of a carpet of perimeter 6 metres. (4 marks)
(b) If the production cost of a carpet is $539, find the perimeter of the carpet. (2 marks)
Sample paper · Paper 1 Q12 Rates, ratios and proportions
Figure
(a) For which part of the journey is the average speed the lowest? Explain your answer. (2 marks)
(b) If the average speed for Part II of the journey is 5656 km/h, when is John at C? (2 marks)
(c) Find the average speed for John driving from A to D in m/s. (3 marks)