()Simplify m−4(mn−2)5 and express your answer with positive indices.
(3 marks)
2020 · Paper 1Q2Polynomials
(a)α2+α−6
(b)α4+α3−6α2
(3 marks)
2020 · Paper 1Q3Approximate 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 1Q4Rates, ratios and proportions
Let a, b and c be non-zero numbers such that ba=76 and 3a=4c. Find a+2bb+2c. (3 marks)
2020 · Paper 1Q5Using percentages
In a recruitment exercise, the number of male applicants is 28% more than the number of female applicants. The difference of the number of male applicants and the number of female applicants is 91. Find the number of male applicants in the recruitment exercise. (4 marks)
2020 · Paper 1Q6Linear inequalities in one unknown
Consider the compound inequality
3−x>27−xor5+x>4
(a)Solve (*).
(b)Write down the greatest negative integer satisfying (*). (4 marks)
2020 · Paper 1Q7Quadratic equations in one unknown
Let p(x)=4x2+12x+c, where c is a constant. The equation p(x)=0 has equal roots. Find
(a)c,
(b)the x-intercept(s) of the graph of y=p(x)−169. (5 marks)
2020 · Paper 1Q8Congruent triangles
In Figure 1, B and D are points lying on AC and AE respectively. BE and CD intersect at the point F. It is given that AB=BE, BD∥CE, ∠CAE=30∘ and ∠ADB=42∘.
(a)Find ∠BEC.
(b)Let ∠BDC=θ. Express ∠CFE in terms of θ. (5 marks)
2020 · Paper 1Q9Measures 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 1Q10Variations
The price of a brand X souvenir of height h cm is \P.\P is partly constant and partly varies as h3. When h=3, \P=59andwhenh=7,\P=691.
(a)Find the price of a brand X souvenir of height 4 cm.
(b)Someone claims that the price of a brand X souvenir of height 5 cm is higher than the total price of two brand X souvenirs of height 4 cm. Is the claim correct? Explain your answer. (2 marks)
2020 · Paper 1Q11Organisation of data
The stem-and-leaf diagram below shows the distribution of the weights (in grams) of the letters in a bag.
(a)Find w.
(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 1Q12Mensuration
The height and the base radius of a solid right circular cone are 36 cm and 15 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,
(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 1Q13More about polynomials
The cubic polynomial f(x) is divisible by x−1. When f(x) is divided by x2−1, the remainder is kx+8, where k is a constant.
(a)Find k. (3 marks)
(b)It is given that x+3 is a factor of f(x). When f(x) is divided by x, the remainder is 24. Someone claims that all the roots of the equation f(x)=0 are integers. Is the claim correct? Explain your answer. (5 marks)
2020 · Paper 1Q14Equations of circles
The coordinates of the points A and B are (−10,0) and (30,0) respectively. The circle C passes through A and B. Denote the centre of C by G. It is given that the y-coordinate of G is −15.
(a)Find the equation of C.
(b)The straight line L passes through B and G. Another straight line ℓ is parallel to L. Let P be a moving point in the rectangular coordinate plane such that the perpendicular distance from P to L is equal to the perpendicular distance from P to ℓ. Denote the locus of P by Γ. It is given that Γ passes through A.
(i)Describe the geometric relationship between Γ and L.
(ii)Find the equation of ℓ.
(iii)Suppose that Γ cuts C at another point H. Someone claims that ∠GAH<70∘. Do you agree? Explain your answer.
2020 · Paper 1Q15More 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 2 plates of different colours are selected. (2 marks)
2020 · Paper 1Q16Arithmetic 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 1st 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 8×1018.
2020 · Paper 1Q17Functions and graphs
Let g(x)=x2−2kx+2k2+4, where k is a real constant.
(a)Using the method of completing the square, express, in terms of k, the coordinates of the vertex of the graph of y=g(x). (2 marks)
(b)On the same rectangular coordinate system, let D and E be the vertex of the graph of y=g(x+2) and the vertex of the graph of y=−g(x−2) respectively. Is there a point F on this rectangular coordinate system such that the coordinates of the circumcentre of ΔDEF are (0,3)? Explain your answer. (4 marks)
2020 · Paper 1Q18Basic properties of circles
In Figure 2, U, V and W are points lying on a circle. Denote the circle by C. TU is the tangent to C at U such that TVW is a straight line.
(a)Prove that ΔUTV∼ΔWTU. (2 marks)
(b)It is given that VW is a diameter of C. Suppose that TU=780 cm and TV=325 cm.
(i)Express the circumference of C in terms of π.
(ii)Someone claims that the perimeter of ΔUVW exceeds 35 m. Do you agree? Explain your answer.
2020 · Paper 1Q19Trigonometry
PQRS is a quadrilateral paper card, where PQ=60 cm, PS=40 cm, ∠PQR=30∘, ∠PRQ=55∘ and ∠QPS=120∘. The paper card is held with QR lying on the horizontal ground as shown in Figure 3.
(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 32∘.
(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 20∘. Is the claim correct? Explain your answer. (7 marks)
2020 · Paper 2Q1Laws of integral indices
(3x−5)−26x=
A54x8.
B32x8.
Cx954.
D3x92.
2020 · Paper 2Q2Formulae
a(a+b)=2(b−a), then b=
A2+aa2+a.
B2+aa2−2a.
C2−aa2+2a.
D2−aa2−a.
2020 · Paper 2Q3Algebraic expressions
4k+35−4k−32=
A16k2−912k−21.
B16k2−912k+9.
C16k2−914k−21.
D16k2−914k+9.
2020 · Paper 2Q4More about polynomials
(3a+2b)(4a−5b)−a(6a+4b)=
A(3a+2b)(2a−5b).
B(3a+2b)(6a−5b).
C(3a−2b)(2a+5b).
D(3a−2b)(6a+5b).
2020 · Paper 2Q5Functions and graphs
Let f(x)=3x2−x−2. If β is a constant, then f(1+β)−f(1−β)=
A2β.
B10β.
C6β2−2.
D6β2−2β.
2020 · Paper 2Q6More about polynomials
Let g(x)=ax3+4ax2−24, where a is a constant. If x+2 is a factor of g(x), then g(2)=
A0.
B0.
C0.
D48.
2020 · Paper 2Q7Identities
If h and k are constants such that (x+h)(x+6)≡(x+4)2+k, then k=
A-28.
B-16.
C-4.
D2.
2020 · Paper 2Q8Equations of straight lines
In the figure, the equations of the straight lines L1 and L2 are x+ay+b=0 and bx+y+c=0 respectively. Which of the following are true?
I. c<0 II. ab<1 III. ac<b
AI and II only
BI and III only
CII and III only
DI, II and III
2020 · Paper 2Q9Using percentages
The cost of a toy is x% lower than its selling price. After selling the toy, the percentage profit is 25%. Find x.
A20
B25
C75
D80
2020 · Paper 2Q10Rates, ratios and proportions
The actual area of a golf course is 0.75 km2. If the area of the course on a map is 100 cm2, then the scale of the map is
A1:250.
B1:5000.
C1:62500.
D1:25000000.
2020 · Paper 2Q11Variations
It is given that w varies as the cube of u and the square root of v. When u=2 and v=4, w=8. When u=4 and v=9, w=
A96.
B324.
C384.
D729.
2020 · Paper 2Q12Arithmetic and geometric sequences and their summations
In the figure, the 1st pattern consists of 3 dots. For any positive integer n, the (n+1)th pattern is formed by adding (2n+1) dots to the nth pattern. Find the number of dots in the 7th pattern.
A15.
B27.
C38.
D51.
2020 · Paper 2Q13Inequalities and linear programming
The solution of 5−4x<9 and 72x−3>1 is
Ax<−1.
Bx>−1.
Cx<5.
Dx>5.
2020 · Paper 2Q14Errors in measurement
In the figure, PQRST is a pentagon, where all the measurements are correct to the nearest cm. Let A cm2 be the actual area of the pentagon. Find the range of values of A.
A27.83≤qA<31.83.
B44.75≤qA<60.75.
C46.75≤qA<63.25.
D48.25≤qA<64.75.
2020 · Paper 2Q15Arc lengths and areas of sectors
The angle of a sector is decreased by 60% but its radius is increased by k%. If the arc length of the sector remains unchanged, find the value of k.
A40.
B60.
C67.
D150.
2020 · Paper 2Q16Mensuration
If the volume of a right circular cylinder of base radius 5a cm and height 7b cm is 525 cm3, then the volume of a right circular cone of base radius 7a cm and height 5b cm is
A175 cm3
B245 cm3
C490 cm3
D735 cm3
2020 · Paper 2Q17Similar 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=QR and PU∥QT∥RS. The ratio of the area of the trapezium QRST is
2020 · Paper 2Q18Similar triangles
In the figure, ABCD is a parallelogram. Let E be a point lying on AD such that AE:ED=2:5. CB is produced to the point F such that BF=DE. Denote the point of intersection of AB and EF by G. It is given that BD and CG intersect at the point H. If the area of △AEG is 48cm2, then the area of △CDH is
A98 cm2
B343 cm2
C420 cm2
D588 cm2
2020 · Paper 2Q19Angles and parallel lines
According to the figure, which of the following must be true?
I. u−v+w=0∘
II. u+v−w=180∘
III. u+v+w=450∘
AI only.
BII only.
CI and III only.
DII and III only.
2020 · Paper 2Q20Polygons
In the figure, ABC is an equilateral triangle and CDE is an isosceles triangle with CD=CE. If ∠DCE=78∘ and ∠ADC=∠CAD=40∘, then ∠CBE=
A14∘.
B19∘.
C24∘.
D29∘.
2020 · Paper 2Q21Pythagoras' theorem
In the figure, ABCD is a rectangle. Let E be a point lying on AD such that BE=8cm and CE=15cm. If BC=17cm, find the area of the rectangle ABCD.
A60cm2.
B68cm2.
C120cm2.
D136cm2.
2020 · Paper 2Q22Basic properties of circles
In the figure, ABCDE is a circle. If AB=10 cm, BC=5 cm, ∠ABC=90∘ and ∠CED=40∘ find CD correct to the nearest cm.
A5 cm.
B6 cm.
C7 cm.
D8 cm.
2020 · Paper 2Q23Trigonometry
A ship is 50 km due west of a lighthouse. If the ship moves in the direction S60∘E, find the shortest distance between the ship and the lighthouse.
A20 km.
B25 km.
C43 km.
D87 km.
2020 · Paper 2Q24Rectangular coordinate system
The point P is translated leftwards by 4 units to the point Q. If the coordinates of the reflection image of Q with respect to the y-axis are (5,−1), then the polar coordinates of P are
A(1,45∘).
B(1,225∘).
C(2,45∘).
D(2,225∘).
2020 · Paper 2Q25Loci
Let A be the point of intersection of the straight lines 9x+4y−7=0 and 9x−4y+7=0. If P is a moving point in the rectangular coordinate plane such that the distance between P and A is 8, then the locus of P is a
Acircle.
Btriangle.
Cquadrilateral.
Dregular hexagon.
2020 · Paper 2Q26Equations of straight lines
The equation of the straight line L is kx+4y−2k=0, where k is a constant. If L is perpendicular to the straight line 6x−9y+4=0, find the y-intercept of L.
A−3
B−2
C2
D3
2020 · Paper 2Q27Equations of circles
The equations of the circles C1 and C2 are 2x2+2y2+4x+8y−149=0 and x2+y2−8x−20y−53=0 respectively. Which of the following is/are true? I. The centre of C1 lies on C2. II. The radii of C1 and C2 are equal. III. C1 and C2 intersect at two distinct points.
AI only
BII only
CI and III only
DII and III only
2020 · Paper 2Q28Probability
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 35.
A21
B31
C32
D83
2020 · Paper 2Q29Measures 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.
A1
B2
C4
D6
2020 · Paper 2Q30Measures of dispersion
Consider the following integers:
33881012mn
Let x, y and z be the median, the mean and the mode of the above integers respectively. If the range of the above integers is 9, which of the following must be true?
I. x=8
II. y=8
III. z=8
AI only
BII only
CI and III only
DII and III only
2020 · Paper 2Q31Exponential and logarithmic functions